[exgcd算最值] luogu 3951

题目

代码

#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<cctype>
#include<ctime>
#include<iostream>
#include<string>
#include<map>
#include<queue>
#include<stack>
#include<set>
#include<vector>
#include<iomanip>
#include<list>
#include<bitset>
#include<sstream>
#include<fstream>
#include<complex>
#include<algorithm>
#if __cplusplus >= 201103L
#include <unordered_map>
#include <unordered_set>
#endif
#define int long long
using namespace std;
const int INF = 0x3f3f3f3f;
int x,y;
void exgcd(int a,int b){
	if(b==0){
		x=1;
		y=0;
		return;
	}
	exgcd(b,a%b);
	int tmp=x;
	x=y;
	y=tmp-(a/b)*y;
}
signed main(){
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	int a,b;
	cin>>a>>b;
	exgcd(a,b); 
	int tmp=(-x)/b;
	x+=tmp*b;
	y-=tmp*y;
	while(x<0){
		x+=b;
		y-=a;
	}
	int xx=x;
	while(x>0){
		x-=b;
		y+=a;
	}
	int yy=y;
	//cout<<xx<<" "<<yy<<endl;
	cout<<a*(xx-1)+b*(yy-1)-1<<endl;
    return 0;
}

本文地址：https://blog.csdn.net/kosf_/article/details/108125685