Basic C Language Programs — Hello World to Sorting

#include <stdio.h>
int main() {
    printf("Hello, World!\\n");
    return 0;
}

#include <stdio.h>
int main() {
    int a, b;
    scanf("%d %d", &a, &b);
    printf("Sum = %d\\n", a + b);
    return 0;
}

#include <stdio.h>
int main() {
    int n;
    scanf("%d", &n);
    if (n % 2 == 0) printf("Even\\n");
    else printf("Odd\\n");
    return 0;
}

#include <stdio.h>
int main() {
    int a, b, c, max;
    scanf("%d %d %d", &a, &b, &c);
    max = a;
    if (b > max) max = b;
    if (c > max) max = c;
    printf("Largest = %d\\n", max);
    return 0;
}

#include <stdio.h>
int main() {
    int n, i;
    long long fact = 1;
    scanf("%d", &n);
    for (i = 1; i <= n; i++) fact *= i;
    printf("Factorial = %lld\\n", fact);
    return 0;
}

#include <stdio.h>
int main() {
    int n, i;
    long long a = 0, b = 1, next;
    scanf("%d", &n);
    for (i = 1; i <= n; i++) {
        printf("%lld ", a);
        next = a + b;
        a = b;
        b = next;
    }
    return 0;
}

#include <stdio.h>
int main() {
    int n, i, prime = 1;
    scanf("%d", &n);
    if (n <= 1) prime = 0;
    for (i = 2; i * i <= n && prime; i++) {
        if (n % i == 0) prime = 0;
    }
    if (prime) printf("Prime\\n");
    else printf("Not Prime\\n");
    return 0;
}

#include <stdio.h>
int main() {
    int n, rev = 0;
    scanf("%d", &n);
    while (n != 0) {
        rev = rev * 10 + n % 10;
        n /= 10;
    }
    printf("Reversed = %d\\n", rev);
    return 0;
}

#include <stdio.h>
int main() {
    int n, temp, rev = 0;
    scanf("%d", &n);
    temp = n;
    while (temp != 0) {
        rev = rev * 10 + temp % 10;
        temp /= 10;
    }
    if (rev == n) printf("Palindrome\\n");
    else printf("Not Palindrome\\n");
    return 0;
}

#include <stdio.h>
int main() {
    int n, temp, rem, sum = 0;
    scanf("%d", &n);
    temp = n;
    while (temp != 0) {
        rem = temp % 10;
        sum += rem * rem * rem;
        temp /= 10;
    }
    if (sum == n) printf("Armstrong\\n");
    else printf("Not Armstrong\\n");
    return 0;
}

#include <stdio.h>
int main() {
    int a, b;
    scanf("%d %d", &a, &b);
    a = a + b;
    b = a - b;
    a = a - b;
    printf("a=%d b=%d\\n", a, b);
    return 0;
}

#include <stdio.h>
int main() {
    int a, b, t;
    scanf("%d %d", &a, &b);
    while (b != 0) {
        t = b;
        b = a % b;
        a = t;
    }
    printf("GCD = %d\\n", a);
    return 0;
}

#include <stdio.h>
int main() {
    int a, b, x, y, t, gcd;
    scanf("%d %d", &a, &b);
    x = a; y = b;
    while (y != 0) {
        t = y;
        y = x % y;
        x = t;
    }
    gcd = x;
    printf("LCM = %d\\n", (a / gcd) * b);
    return 0;
}

#include <stdio.h>
int main() {
    int n, arr[32], i = 0, j;
    scanf("%d", &n);
    if (n == 0) { printf("0\\n"); return 0; }
    while (n > 0) {
        arr[i++] = n % 2;
        n /= 2;
    }
    for (j = i - 1; j >= 0; j--) printf("%d", arr[j]);
    printf("\\n");
    return 0;
}

#include <stdio.h>
int main() {
    int n, count = 0;
    scanf("%d", &n);
    if (n == 0) count = 1;
    while (n != 0) {
        count++;
        n /= 10;
    }
    printf("Digits = %d\\n", count);
    return 0;
}

#include <stdio.h>
int main() {
    int n, sum = 0;
    scanf("%d", &n);
    while (n != 0) {
        sum += n % 10;
        n /= 10;
    }
    printf("Sum of digits = %d\\n", sum);
    return 0;
}

#include <stdio.h>
int main() {
    int n, i, key, pos = -1;
    scanf("%d", &n);
    int a[100];
    for (i = 0; i < n; i++) scanf("%d", &a[i]);
    scanf("%d", &key);
    for (i = 0; i < n; i++) {
        if (a[i] == key) { pos = i; break; }
    }
    if (pos != -1) printf("Found at index %d\\n", pos);
    else printf("Not found\\n");
    return 0;
}

#include <stdio.h>
int main() {
    int n, i, j, t;
    scanf("%d", &n);
    int a[100];
    for (i = 0; i < n; i++) scanf("%d", &a[i]);
    for (i = 0; i < n - 1; i++) {
        for (j = 0; j < n - i - 1; j++) {
            if (a[j] > a[j + 1]) {
                t = a[j];
                a[j] = a[j + 1];
                a[j + 1] = t;
            }
        }
    }
    for (i = 0; i < n; i++) printf("%d ", a[i]);
    return 0;
}

#include <stdio.h>
int main() {
    int a[2][2], b[2][2], c[2][2], i, j;
    for (i = 0; i < 2; i++)
        for (j = 0; j < 2; j++)
            scanf("%d", &a[i][j]);
    for (i = 0; i < 2; i++)
        for (j = 0; j < 2; j++)
            scanf("%d", &b[i][j]);
    for (i = 0; i < 2; i++)
        for (j = 0; j < 2; j++)
            c[i][j] = a[i][j] + b[i][j];
    for (i = 0; i < 2; i++) {
        for (j = 0; j < 2; j++) printf("%d ", c[i][j]);
        printf("\\n");
    }
    return 0;
}

#include <stdio.h>
int main() {
    char s[200];
    int i = 0;
    scanf("%199s", s);
    while (s[i] != '\\0') i++;
    printf("Length = %d\\n", i);
    return 0;
}