题解 | #[NOIP2015]金币#

#include <stdio.h>

int main() {
    int k, sum = 0, count = 0;
    scanf("%d", &k);
    for (int i = 1; i <= k; i++) {
        for (int j = 0; j < i; j++) {
            sum += i;
            count++;
            if (count == k) {
                printf("%d", sum);
                return 0;
            }
        }
    }
    return 0;
}