题目详情

解题代码

#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;

const int N =  2.5e7+10;

struct Sum
{
    
    int s,c,d;
    
    bool operator< (const Sum &t)const
    {
    
        if(s!=t.s) return s<t.s;
        if(c!=t.c) return c<t.c;
        return d<t.d;
    }
}sum[N];

int n,m;

int main()
{
    
    cin >> n ;
    
    for(int c=0;c*c<=n;c++)
        for(int d=c;c*c+d*d<=n;d++)
            sum[m++]={
    c*c+d*d,c,d};
            
    sort(sum,sum+m);
    
     for(int a=0;a*a<=n;a++)
        for(int b=0;b*b+a*a<=n;b++)
        {
    
            int t=n-a*a-b*b;
            int l=0,r=m-1;
            
            while(l<r)
            {
    
                int mid = l+r>>1;
                if(sum[mid].s>=t) r=mid;
                else l=mid+1;
            }
            if (sum[l].s == t)
            {
    
                printf("%d %d %d %d\n", a, b, sum[l].c, sum[l].d);
                return 0;
            }
        }
    
    return 0;
    
}