题解 | #小乐乐求和#

#include <stdio.h>

int main() {
    int num;
    scanf("%d",&num);
    long sum = 0;//用long类型计算
    int arr[num];
    for (int i = 0; i < num; i++) {
       sum =sum +i+1;
    }
    printf("%ld\n",sum);
    return 0;
}