HDU - 6441（费马大定理）

链接：HDU - 6441

题意：已知 n，a，求 b，c 使 a^n + b^n = c^n 成立。

题解：费马大定理

1.a^n + b^n = c^n，当 n > 2 时无解；

2.

当 a 为奇数

a = 2 * k + 1;

c = k ^ 2 + (k + 1) ^ 2;

b = c - 1;

当 a 为偶数

a = 2 * k + 2;

c = 1 + (k + 1) ^ 2;

b = c - 2;

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

const double EPS = 1e-;
const int INF = 0x3f3f3f3f;
const int mod = 1e9 + ;
const int maxn = 1e5 + ;
long long n, a, b, c;

int main()
{
    int T;
    scanf("%d", &T);
    while(T--){
        scanf("%lld%lld", &n, &a);

        if(n ==  || n > ){
            puts("-1 -1");
            continue;
        }

        if(n == ){
            printf("%lld %lld\n", a, a<<);
            continue;
        }

        if(a & 1LL){
            long long k = a / ;
            c = k * k + (k + ) * (k + );
            b = c - ;
        }
        else{
            long long k = a /  - ;
            c =  + (k + ) * (k + );
            b = c - ;
        }

        printf("%lld %lld\n", b, c);
    }

    return ;
}