《牛客2021年儿童节比赛D》
同余方程没推好。。
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include<bits/stdc++.h> using namespace std; typedef long long LL; typedef pair<int,set<int>> pii; const int N = 1e5 + 5; const int M = 1e5 + 5; const LL Mod = 998244353; #define pi acos(-1) #define INF 1e9 #define dbg(ax) cout << "now this num is " << ax << endl; namespace FASTIO{ inline int read(){ int x = 0,f = 1;char c = getchar(); while(c < '0' || c > '9'){if(c == '-') f = -1;c = getchar();} while(c >= '0' && c <= '9'){x = (x<<1)+(x<<3)+(c^48);c = getchar();} return x*f; } } using namespace FASTIO; LL exgcd(LL a,LL b,LL &x,LL &y){ if(b == 0) { x = 1,y = 0; return a; } int t = exgcd(b,a%b,y,x); y -= a/b*x; return t; } int n,a,b; int main() { n = read(),a = read(),b = read(); LL gcd = __gcd(a,b); LL p,k; LL ta = exgcd(gcd,n,p,k); if((n - 1) % ta != 0) printf("-1\n"); else { LL x,y; LL g = exgcd(a,b,x,y); p = p * (n - 1) / ta; x = x * p; y = y * p; if(x < 0) x = x + 1LL * (abs(x / n) + 1) * n; if(y < 0) y = y + 1LL * (abs(y / n) + 1) * n; printf("%lld %lld\n",x,y); } //system("pause"); return 0; }