hdu 4342 History repeat itself 夜

http://acm.hdu.edu.cn/showproblem.php?pid=4342

当出现和long long相关的操作时  一定要注意定义的int 变量在相加或相乘时是否会越界

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<map>
#include<cmath>
#define LL long long

using namespace std;

const int N=100005;
LL asum[N];
LL num[N];
void bigen()
{
    asum[1]=1;
    num[1]=0;
    for(LL i=2;i<N;++i)//i也得变成long long 因为相乘时会超过int
    {
        num[i]=(i*i-(i-1)*(i-1))-1+num[i-1];
        asum[i]=(i*i-(i-1)*(i-1))*(i-1)+1+asum[i-1];
    }
}
int main()
{
    //freopen("data.txt","r",stdin);
    int T;
    bigen();
    cin>>T;
    while(T--)
    {
        LL n;
        cin>>n;
        LL m;
        for(int i=1;i<N;++i)
        {
            if(num[i]>=n)
            {
                m=i-1;
                break;
            }
        }
        LL ans1=m*m+(n-num[m]);
        LL ans2=asum[m]+(n-num[m])*m;
        cout<<ans1<<" "<<ans2<<endl;
    }
    return 0;
}

  

原文地址:https://www.cnblogs.com/liulangye/p/2627902.html