余数之和 (暴力,思维,前缀和) HQG_AC

bbb

#include <bits/stdc++.h>
using namespace std;

typedef long long ll ;

ll ans,k,n,check;
ll f(ll l,ll r){
    l--;
    return (r+1)*r/2-(l+1)*l/2;
}
int main(){
    scanf("%lld%lld",&n,&k);
    for(ll i=1,last;i<=min(n,k);i=last+1){
        last=min(n,k/(k/i));
        ans+=(k/i)*f(i,last);
    }
    printf("%lld\n",k*n-ans);
}

猜你喜欢

转载自blog.csdn.net/HQG_AC/article/details/81226487
今日推荐