Summation and Factorial

Summation of Natural Number From 1 to 10

#include<stdio.h>
int main(){
    int i = 0, n = 10, sum = 0;

    for(i=1; i<=n; i++){
        sum = sum + i;
    }
    printf("%d\n",sum);
    
    return 0;
}

#include<stdio.h>
int main(){
    int n = 5, i, sum, f;
    //scanf("%d", &n);
    //printf("%d", n);

    //1 + 2 + 3 + 4 ............... + N;
    for( i=1, sum=0; i<=n; i++){
        //sum = sum + i;
        sum += i;
    }
    printf("%d\n", sum);

    //1 + 3 + 5 ............... + N;
    for( i=1, sum=0; i<=n; i+=2){
        sum += i;
    }
    printf("%d\n", sum);

    //2^3 + 4^3 + 6^3 + 8^3 + ...... + N^3
    for( i=2, sum=0; i<=n; i+=2){
        sum += i*i*i;
    }
    printf("%d\n", sum);

    


    return 0;
}

#include<stdio.h>
int main(){
    int c;
    int sum = 0;

    c = 2;
    while(c <= 6){
        sum += c;
        c += 2;
    }
    printf("%d\n", sum);

    return 0;
}

Factorial (n)

#include<stdio.h>
int main(){
    int i=0, n=5, f=1;

    for(i=1; i<=n; i++){
        f *= i;
    }
    printf("Factorial (%d) = %d", n, f);
    return 0;
}
// Factorial(n) = n! = 1*2*3* ... *(n-1)*n
// Factorial(5) = 5! =  1 * 2 * 3 * 4 * 5 = 120