对于每一个正整数,\((n + 1)^2 - (n + 1)\) = \((-n) ^ 2 - (-n)\)

#include<bits/stdc++.h>

using namespace std;
int c,d;
int main() {
    //freopen("5.in.txt","r",stdin);
    //freopen("5.out.txt","w",stdout);
    int ans = 0;
    cin>>c>>d;
    for(int i = 1;i <= 1e8;i++) {
        if(i * i - i > d) {
            printf("%d\n",ans);
            return 0; 
        }
        if(i * i - i >= c and i * i - i <= d) {
            ans++;
        }
    }
}