思路:
官方题解:
代码:
#include<bits/stdc++.h> using namespace std; #define ll long long int main() { int t; scanf("%d",&t); while(t--) { ll n,m,ans; scanf("%lld%lld",&n,&m); if(m<n-1) { ans=m*2+(m-1)*m*2+(n*(n-1)-m*2-(m-1)*m)*n; } else if(m<n*(n-1)/2) { ans=(n-1)*2+(n-2)*(n-1)*2; ll t=m-(n-1); ans-=t*2; } else { ans=(n-1)*n; } printf("%lld ",ans); } return 0; }