【数论】 nefu 702 The minimum square sum

数论这种东西。。。记住结论就好。。。

题目描述。。

Given a prime p (p<10⁸),you are to find min{x²+y²},where x and y belongs to positive integer, so that x²+y²=0 (mod p).

#include <iostream>  #include <sstream>  #include <algorithm>  #include <vector>  #include <queue>  #include <stack>  #include <map>  #include <set>  #include <bitset>  #include <cstdio>  #include <cstring>  #include <cstdlib>  #include <cmath>  #include <climits>  #define maxn 1105#define eps 1e-6 #define mod 10007 #define INF 99999999  #define lowbit(x) (x&(-x))  #define lson o<<1, L, mid  #define rson o<<1 | 1, mid+1, R  typedef long long LL;using namespace std;int main(void){LL p;while(scanf("%I64d", &p)!=EOF){if(p == 2) printf("%I64d\n", p);else if((p-3)%4 == 0) printf("%I64d\n", 2*p*p);else printf("%I64d\n", p);}return 0;}