Codes & Snippets

#include<stdio.h>
#include<math.h>
int main()
{
    printf("INSTRUCTIONS: Enter the side length (l) of the square when prompted.\n");
	float l,A,P,D;
	printf("enter the value of l");
	scanf("%f",&l);
	A=l*l;
	P=4*l;
	D=sqrt(2)*l;
	printf("The area of square is %f\n perimeter is %f\n diagonal is %f",A,P,D);
	return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
    printf("INSTRUCTIONS: Enter the radius (r) and height (h) of the cylinder when prompted.\n");
	float r,h,A,V;
	printf("enter the value of r");
	scanf("%f",&r);
	printf("enter the value of h");
	scanf("%f",&h);
	A=3.14*r*(r+h);
	V=3.14*r*h;
	printf("The area of  cylinder is %f\n volume is %f ",A,V);
	return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
    printf("INSTRUCTIONS: Enter initial velocity (u), acceleration (a), start time (t1), end time (t2), and time interval (t).\n");
	float i,a,u,t,t1,t2,s;
	printf("enter the value of u: ");
	scanf("%f",&u);
	printf("enter the value of a: ");
	scanf("%f",&a);
	printf("enter the value of t1: ");
	scanf("%f",&t1);
	printf("enter the value of t2: ");
	scanf("%f",&t2);
	printf("enter the value of t: ");
	scanf("%f",&t);
	for(i=t1;i<=t2;i=i+t)
	{
    s=(u*i)+(0.5*a*i*i);
	printf("The value of s is %f\n",s);
	}
	return 0;
}

#include<stdio.h>
int main()
{
    printf("INSTRUCTIONS: Enter an operator (+, -, /, %%) followed by two integer operands.\n");
	int a,b;
	char op;
	printf("enter the value of op: ");
	scanf(" %c",&op);
	printf("enter the value of a: ");
	scanf("%d",&a);
	printf("enter the value of b: ");
	scanf("%d",&b);
	switch(op)
	{
		case '+': printf("%d",(a+b));
			break;
		case '-': printf("%d",(a-b));
			break;
		case '/': printf("%d",(a/b));
			break;	
		case '%': printf("%d",(a%b));
			break;
		default:
			printf("Invalid operand!");
	}
	return 0;
}

#include<stdio.h>

int main()
{
    printf("INSTRUCTIONS: Enter a positive integer to calculate the sum of its digits.\n");
	int n,sum=0;
	printf("enter the +ve no.");
	scanf("%d",&n);
	while(n>0)
	{
		sum=sum+n%10;
		n=n/10;
	}
	printf("Sum of individual integer is %d",sum);
	return 0;
}

#include<stdio.h>

int main()
{
    printf("INSTRUCTIONS: Enter the number of terms for the Fibonacci series.\n");
	int a,n,t1=0,t2=1,t3=t1+t2;
	printf("enter the number of terms:");
	scanf("%d",&n);
	printf("fibonacci series is\n%d\n%d\n",t1,t2);
	for(a=3;a<=n;a++)
	{
		printf("%d\n",t3);
		t1=t2;
		t2=t3;
		t3=t1+t2;
	}
	return 0;
}

#include<stdio.h>

int main()
{
    printf("INSTRUCTIONS: Enter the upper limit of the interval to find prime numbers from 1 to that limit.\n");
	int a=1,b,n,count=2;
	printf("Enter the last number of the interval: ");
	scanf("%d",&b);
	printf("prime number between 1 and %d is\n ",b);
	for(n=1;n<=b;n++)
	{
		if(n%count!=0)
		
		printf("%d\n",n);
	}
	return 0;
}

#include <stdio.h>
#include <math.h>
int main()
{
    printf("INSTRUCTIONS: Enter the value of X to calculate the series sum.\n");
    int counter,f_coun;
    float sum=0,x,power,fact;

    printf("\tEQUATION SERIES : 1- X^2/2! + X^4/4! - X^6/6! + X^8/8! - X^10/10!");

    printf("\n\tENTER VALUE OF X : ");
    scanf("%f",&x);

    for(counter=0, power=0; power<=10; counter++,power=power+2)
    {
        fact=1;
        for(f_coun=power; f_coun>=1; f_coun--)
            fact *= f_coun;
        sum=sum+(pow(-1,counter)*(pow(x,power)/fact));
    }

    printf("SUM : %f",sum);

}

#include<stdio.h>
#include<math.h>
int main()
{
    printf("INSTRUCTIONS: Enter length (l) and breadth (b) of the rectangle when prompted.\n");
	float l,b,A,P,D;
	printf("enter the value of l");
	scanf("%f",&l);
	printf("enter the value of b");
	scanf("%f",&b);
	A=l*b;
	P=2*(l+b);
	D=sqrt(l*l+b*b);
	printf("The area of rectangle is %f\n perimeter is %f\n diagonal is %f",A,P,D);
	return 0;
}

#include <stdio.h>
#include <string.h>

void reverse_word(char* word) {
    int length = strlen(word);
    for(int i = 0; i < length / 2; i++) {
        char temp = word[i];
        word[i] = word[length - i - 1];
        word[length - i - 1] = temp;
    }
}

int main() {
    printf("INSTRUCTIONS: Enter a string to reverse its words.\n");
    char str[100];
    printf("Enter a string: ");
    fgets(str, sizeof(str), stdin); // read string including spaces
    str[strcspn(str, "\n")] = '\0'; // remove trailing newline character

    char* token = strtok(str, " ");
    while(token != NULL) {
        reverse_word(token);
        printf("%s ", token);
        token = strtok(NULL, " ");
    }


    return 0;
}

#include <stdio.h>
#include <string.h>

#define MAX_STRINGS 10
#define MAX_LENGTH 100

int main() {
    printf("INSTRUCTIONS: Enter multiple lines of text. Type a semicolon ';' on a new line to finish input.\n");
    char strings[MAX_STRINGS][MAX_LENGTH];
    int string_count = 0;
    char temp[MAX_LENGTH];

    printf("Enter multiline string input, press enter key to input each string, end input with a semicolon:\n");

    while (1) {
        fgets(temp, MAX_LENGTH, stdin);

        if (temp[strlen(temp) - 1] == '\n') {
            temp[strlen(temp) - 1] = '\0';
        }

        if (strcmp(temp, ";") == 0) {

            break;
        }

        strcpy(strings[string_count++], temp);
    }

    printf("\nIndividual string length results:\n");

    for (int i = 0; i < string_count; i++) {
        printf("String %d: Length %zu\n", i + 1, strlen(strings[i]));
    }

    return 0;
}

#include <stdio.h>
#include <string.h>
int main()
{
    printf("INSTRUCTIONS: Enter a Roman numeral (e.g., XIV, MMXX) to convert to decimal.\n");
   char rom[30];
   int a[30], l, i, k, dec=0;
   printf("Enter the roman number\n");
   scanf("%s", rom);
   l =strlen(rom);
   for(i = 0; i < l; i++)
   {
      switch (rom[i])
      {
     case 'I':  a[i] = 1;
            break;
     case 'V':  a[i] = 5;
            break;
     case 'X':  a[i] = 10;
            break;
     case 'L':  a[i] = 50;
            break;
     case 'C':  a[i] = 100;
            break;
     case 'D':  dec = dec + 500;

            break;
     case 'M':  a[i] = 1000;
            break;
     default :  printf("Invalid choice");
            break;
      }
   }
   k = a[l - 1];
   for(i = l - 1; i > 0; i--)
   {
      if(a[i] > a[i - 1])
      {
     k = k - a[i - 1];
      }
      if(a[i] <= a[i - 1])
      {
     k = k + a[i - 1];
      }
   }
   printf("decimal equivalent is %d", k);
   return 0;
}

#include <stdio.h>

int recgcd(int x, int y);
int nonrecgcd(int x, int y);

int main()
{
    printf("INSTRUCTIONS: Enter two integers to calculate their GCD.\n");
   int a, b, c, d;
   printf("Enter two numbers a, b\n");
   scanf("%d%d", &a, &b);
   c = recgcd(a, b);
   printf("The gcd of two numbers using recursion is %d\n", c);
   d = nonrecgcd(a, b);
   printf("The gcd of two numbers using nonrecursion is %d", d);
   return 0;
}
int recgcd(int x, int y)
{
   if(y == 0)
   {
      return(x);
   }
   else
   {
     return(recgcd(y, x % y));
   }
}
int nonrecgcd(int x, int y)
{
   int z;

   while(x % y != 0)
   {
    z = x % y;
    x = y;
    y = z;
   }
   return(y);
}

# include<stdio.h>
# include<math.h>
int main ()
   {
    printf("INSTRUCTIONS: Enter coefficients a, b, and c when prompted.\n");
    float a,b,c,r1,r2,d;
    printf ("Enter the values of a b c: ");
    scanf (" %f %f %f", &a, &b, &c);  
    d= b*b - 4*a*c;    
    if (d>0)
	{
        r1 = (-b+sqrt(d)) / (2*a);
        r2 = (-b-sqrt(d)) / (2*a);
        printf ("The real roots = %f %f", r1, r2);
    }
    else if (d==0) 
	{
        r1 = -b/(2*a);
        r2 = -b/(2*a);
        printf ("Roots are equal =%f %f", r1, r2);
    }
    else
        printf("Roots are imaginary");
    
    return 0;
}

#include <stdio.h>
int main()
{
    printf("INSTRUCTIONS: Enter the size of the array and then its integer elements.\n");
   int a[25], i, large, small, n;
   printf("Enter the size of array(max 25)\n");
   scanf("%d", &n);
   printf("Enter any %d integer array elements\n",n);
   for(i = 0; i < n; i++)
   {
    scanf("%d", &a[i]);
   }
   large = a[0];
   small = a[0];
   for(i = 1; i < n ; i++)
   {
      if(a[i] > large)
      {
    large = a[i];
      }
      if(a[i] < small)
      {
    small = a[i];
      }

   }
   printf("The largest element from the given array is %d \nThe smallest element  from the given array is %d", large, small);
   return 0;
}

#include <stdio.h>
#include <stdlib.h>
int main()
{
    printf("INSTRUCTIONS: Enter initial array size and elements, then new size to resize.\n");
    int *array, size, new_size, i;
    printf("Enter the size of the array: ");
    scanf("%d", &size);
    array = (int *)malloc(size * sizeof(int));
    printf("Enter the elements of the array: ");
    for (i = 0; i < size; i++)
    {
        scanf("%d", &array[i]);
    }
    printf("Enter the new size of the array: ");
    scanf("%d", &new_size);
    if (new_size > size)
    {
        array = (int *)realloc(array, new_size * sizeof(int));
        for (i = size; i < new_size; i++)
        {
            array[i] = 0;
        }
    }
    else if (new_size < size)
    {
        array = (int *)realloc(array, new_size * sizeof(int));
    }

    printf("The new array is: ");
    for (i = 0; i < new_size; i++)
    {
        printf("%d ", array[i]);
    }
    free(array);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
int main() {
    printf("INSTRUCTIONS: Enter dimensions and elements, then choose to increase/decrease rows.\n");
    int **matrix, rows, cols, i, j;
    // Initialize the 2D array
    printf("Enter the number of rows: ");
    scanf("%d", &rows);
    printf("Enter the number of columns: ");
    scanf("%d", &cols);
    matrix = (int **)malloc(rows * sizeof(int *));
    for (i = 0; i < rows; i++) {
        matrix[i] = (int *)malloc(cols * sizeof(int));
    }
    // Initialize the elements of the matrix
    printf("Enter the elements of the matrix:\n");
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            scanf("%d", &matrix[i][j]);
        }
    }
    // Display the original matrix
    printf("Original Matrix:\n");
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            printf("%d\t", matrix[i][j]);
        }
        printf("\n");
    }
    // Increase or decrease the number of subarrays
    int choice;
    printf("\nEnter 1 to increase the number of subarrays, 2 to decrease: ");
    scanf("%d", &choice);
    if (choice == 1) {
        // Increase the number of subarrays
        int newRows;
        printf("Enter the number of additional rows: ");
        scanf("%d", &newRows);
        matrix = (int **)realloc(matrix, (rows + newRows) * sizeof(int *));
        for (i = rows; i < rows + newRows; i++) {
            matrix[i] = (int *)malloc(cols * sizeof(int));
        }
        rows += newRows;
    } else if (choice == 2) {
        // Decrease the number of subarrays
        int removeRows;
        printf("Enter the number of rows to remove: ");
        scanf("%d", &removeRows);
        if (removeRows <= rows) {
            matrix = (int **)realloc(matrix, (rows - removeRows) * sizeof(int *));
            rows -= removeRows;
        } else {
            printf("Error: Cannot remove more rows than present.\n");
        }
    } else {
        printf("Invalid choice.\n");
    }
    // Display the modified matrix
    printf("\nModified Matrix:\n");
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            printf("%d\t", matrix[i][j]);
        }
        printf("\n");
    }
    // Deallocate memory
   for (i = 0; i < rows; i++) 
        free(
            
matrix[i]);
   
    free(matrix);
    return 0;

}

#include <stdio.h>
#define ADD(a,b) a+b
#define SUB(a,b) a-b
#define MULTIPLY(a,b) a*b
#define DIVIDE(a,b) a/b
int main()
{
    printf("INSTRUCTIONS: Demonstrates macro usage. No user input required.\n");
    int a=10,b=5;
    printf("addition value is %d\n",ADD(a,b));
    printf("Sub value is %d\n",SUB(a,b));
    printf("multiply value is %d\n",MULTIPLY(a,b));
    printf("divide value is %d\n",DIVIDE(a,b));
    return 0;
}

#include <iostream>
using namespace std;

int main() {
    cout << "INSTRUCTIONS: Enter a number to check if it is prime." << endl;
    int n;
    cin >> n;
    if (n <= 1) {
        cout << "Not Prime";
        return 0;
    }
    for (int i = 2; i * i <= n; i++) {
        if (n % i == 0) {
            cout << "Not Prime";
            return 0;
        }
    }
    cout << "Prime";
    return 0;
}

#include <iostream>
#include <vector>
using namespace std;

int main() {
    cout << "INSTRUCTIONS: Enter size n, n array elements, and then the target value." << endl;
    int n, target;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];
    cin >> target;

    int l = 0, r = n - 1;
    while (l <= r) {
        int mid = (l + r) / 2;
        if (a[mid] == target) {
            cout << mid;
            return 0;
        } else if (a[mid] < target)
            l = mid + 1;
        else
            r = mid - 1;
    }
    cout << l;
}

#include <iostream>
#include <vector>
#include <numeric>
#include <algorithm>
using namespace std;

int main() {
    cout << "INSTRUCTIONS: Enter the number of children n, followed by n ratings." << endl;
    int n;
    cin >> n;
    vector<int> rating(n), candy(n, 1);
    for (int i = 0; i < n; i++) cin >> rating[i];

    for (int i = 1; i < n; i++)
        if (rating[i] > rating[i - 1])
            candy[i] = candy[i - 1] + 1;

    for (int i = n - 2; i >= 0; i--)
        if (rating[i] > rating[i + 1])
            candy[i] = max(candy[i], candy[i + 1] + 1);

    cout << accumulate(candy.begin(), candy.end(), 0);
}

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

bool canPlace(vector<int>& stalls, int c, int dist) {
    int count = 1, last = stalls[0];
    for (int i = 1; i < stalls.size(); i++) {
        if (stalls[i] - last >= dist) {
            count++;
            last = stalls[i];
        }
    }
    return count >= c;
}

int main() {
    cout << "INSTRUCTIONS: Enter n (stalls) and c (cows), followed by n stall positions." << endl;
    int n, c;
    cin >> n >> c;
    vector<int> stalls(n);
    for (int i = 0; i < n; i++) cin >> stalls[i];
    sort(stalls.begin(), stalls.end());

    int low = 0, high = stalls[n - 1], ans = 0;
    while (low <= high) {
        int mid = (low + high) / 2;
        if (canPlace(stalls, c, mid)) {
            ans = mid;
            low = mid + 1;
        } else
            high = mid - 1;
    }
    cout << ans;
}

#include <iostream>
#include <vector>
using namespace std;

bool dfs(int v, int parent, vector<vector<int>>& adj, vector<bool>& visited) {
    visited[v] = true;
    for (int u : adj[v]) {
        if (!visited[u]) {
            if (dfs(u, v, adj, visited)) return true;
        } else if (u != parent)
            return true;
    }
    return false;
}

int main() {
    cout << "INSTRUCTIONS: Enter V (vertices) and E (edges), followed by E pairs of edges (u v)." << endl;
    int V, E;
    cin >> V >> E;
    vector<vector<int>> adj(V);
    vector<bool> visited(V, false);

    for (int i = 0; i < E; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    for (int i = 0; i < V; i++)
        if (!visited[i] && dfs(i, -1, adj, visited)) {
            cout << "Cycle Found";
            return 0;
        }

    cout << "No Cycle";
}

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

vector<vector<int>> bridges;
vector<int> disc, low;
int timeDfs = 0;

void dfs(int u, int parent, vector<vector<int>>& adj) {
    disc[u] = low[u] = ++timeDfs;
    for (int v : adj[u]) {
        if (v == parent) continue;
        if (!disc[v]) {
            dfs(v, u, adj);
            low[u] = min(low[u], low[v]);
            if (low[v] > disc[u])
                bridges.push_back({u, v});
        } else
            low[u] = min(low[u], disc[v]);
    }
}

int main() {
    cout << "INSTRUCTIONS: Enter n (nodes) and e (edges), followed by e pairs of edges (u v)." << endl;
    int n, e;
    cin >> n >> e;
    vector<vector<int>> adj(n);
    disc.assign(n, 0);
    low.assign(n, 0);

    for (int i = 0; i < e; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    dfs(0, -1, adj);
    for (auto& b : bridges)
        cout << b[0] << " " << b[1] << endl;
}

#include <iostream>
#include <vector>
using namespace std;

void dfs(int i, int j, vector<vector<char>>& g) {
    if (i < 0 || j < 0 || i >= g.size() || j >= g[0].size() || g[i][j] == '0')
        return;
    g[i][j] = '0';
    dfs(i + 1, j, g);
    dfs(i - 1, j, g);
    dfs(i, j + 1, g);
    dfs(i, j - 1, g);
}

int main() {
    cout << "INSTRUCTIONS: Enter dimensions N and M, then the grid row by row." << endl;
    int n, m;
    cin >> n >> m;
    vector<vector<char>> grid(n, vector<char>(m));
    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            cin >> grid[i][j];

    int count = 0;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            if (grid[i][j] == '1') {
                count++;
                dfs(i, j, grid);
            }

    cout << count;
}

#include <iostream>
#include <vector>
#include <queue>
#include <tuple>
using namespace std;

int main() {
    cout << "INSTRUCTIONS: Enter dimensions N and M, then the grid (0=Empty, 1=Fresh, 2=Rotten)." << endl;
    int n, m;
    cin >> n >> m;
    vector<vector<int>> grid(n, vector<int>(m));
    queue<pair<int,int>> q;
    int fresh = 0, time = 0;

    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++) {
            cin >> grid[i][j];
            if (grid[i][j] == 2) q.push({i, j});
            if (grid[i][j] == 1) fresh++;
        }

    int dirs[4][2] = {{1,0},{-1,0},{0,1},{0,-1}};
    while (!q.empty() && fresh) {
        int sz = q.size();
        while (sz--) {
            auto [x, y] = q.front(); q.pop();
            for (auto& d : dirs) {
                int nx = x + d[0], ny = y + d[1];
                if (nx>=0 && ny>=0 && nx<n && ny<m && grid[nx][ny]==1) {
                    grid[nx][ny] = 2;
                    fresh--;
                    q.push({nx, ny});
                }
            }
        }
        time++;
    }
    cout << (fresh ? -1 : time);
}

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

int main() {
    cout << "INSTRUCTIONS: Enter two strings to calculate edit distance." << endl;
    string a, b;
    cin >> a >> b;
    int n = a.size(), m = b.size();
    vector<vector<int>> dp(n + 1, vector<int>(m + 1));

    for (int i = 0; i <= n; i++) dp[i][0] = i;
    for (int j = 0; j <= m; j++) dp[0][j] = j;

    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            if (a[i - 1] == b[j - 1])
                dp[i][j] = dp[i - 1][j - 1];
            else
                dp[i][j] = 1 + min({dp[i - 1][j], dp[i][j - 1], dp[i - 1][j - 1]});

    cout << dp[n][m];
}

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
    cout << "INSTRUCTIONS: Enter dimensions N M, then grid rows." << endl;
    int n, m;
    cin >> n >> m;
    vector<vector<int>> g(n, vector<int>(m));
    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            cin >> g[i][j];

    for (int i = 1; i < n; i++) g[i][0] += g[i - 1][0];
    for (int j = 1; j < m; j++) g[0][j] += g[0][j - 1];

    for (int i = 1; i < n; i++)
        for (int j = 1; j < m; j++)
            g[i][j] += min(g[i - 1][j], g[i][j - 1]);

    cout << g[n - 1][m - 1];
}

#include <iostream>
#include <string>
#include <stack>
#include <algorithm>
using namespace std;

int main() {
    cout << "INSTRUCTIONS: Enter the number string and k." << endl;
    string num;
    int k;
    cin >> num >> k;
    stack<char> st;

    for (char c : num) {
        while (!st.empty() && k && st.top() > c) {
            st.pop();
            k--;
        }
        st.push(c);
    }
    while (k--) st.pop();

    string res = "";
    while (!st.empty()) {
        res += st.top();
        st.pop();
    }
    reverse(res.begin(), res.end());
    res.erase(0, res.find_first_not_of('0'));

    cout << (res.empty() ? "0" : res);
}

#include <iostream>
#include <vector>
using namespace std;

int main() {
    cout << "INSTRUCTIONS: Enter dimensions m and n." << endl;
    int m, n;
    cin >> m >> n;
    vector<vector<int>> dp(m, vector<int>(n, 1));

    for (int i = 1; i < m; i++)
        for (int j = 1; j < n; j++)
            dp[i][j] = dp[i - 1][j] + dp[i][j - 1];

    cout << dp[m - 1][n - 1];
}