题解 | 牛牛学数列
牛牛学数列
https://www.nowcoder.com/practice/0b97367cd2184c12a0e02f7c223aee11
#include <stdio.h> int main() { int num = 0; int sum = 0; int i = 0; scanf("%d",&num); for (i = 1; i <= num; i++) { if (i % 2 == 0) { sum -= i; } else { sum += i; } } printf("%d",sum); return 0; }