POJ 1305

毕达哥斯三元组的模板题

练习练习

#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<cmath>
using namespace std;
typedef long long ll;
const int maxn = 1e6 +131;
bool Jug[maxn];
int ans, sum;

int gcd(int a,int b)
{
    return b == 0 ? a : gcd(b,a%b);
}

void solve(int);

int main()
{
    int n;
    while(~scanf("%d",&n))
    {
        solve(n);
    }
    return 0;
}

void solve(int n)
{
    memset(Jug,false,sizeof(Jug));
    ans = sum = 0;
    int tmp = int(sqrt(n +1.0));
    for(int i = 1; i <= tmp; ++i)
    {
        for(int j = i+1; j <= tmp; ++j)
        {
            if(i*i + j*j > n) break;
            if(gcd(i,j) == 1 && (i % 2 != j % 2))
            {
                int x = j * j - i * i;
                int y = 2 * i * j;
                int z = j*j + i*i;
                if(x*x + y*y == z*z)
                {
                    ans ++;
                    for(int i = 1; ; i ++)
                    {
                        if(i * z > n) break;
                        Jug[i*x] = true;
                        Jug[i*y] = true;
                        Jug[i*z] = true;
                    }
                }
            }
        }
    }
    for(int i = 1; i <= n; ++i) if(Jug[i] == false) sum++;
    printf("%d %d\n",ans,sum);
}