View Code of Problem 30

#include <stdio.h>

int main(int argc, const char * argv[]) {
    int n;
    int i, sum = 0;
    while(scanf("%d",&n) != EOF) {
        sum = 0;
        for(i = 1; i <= n; i++) {
            sum += i;
        }
        printf("%d\n",sum);
    }
    return 0;
}