备战NOIP——模板复习5

这里只有模板，并不作讲解，仅为路过的各位做一个参考以及用做自己复习的资料，转载注明出处。

欧几里德算法(gcd)模板

gcd

/*Copyright: Copyright (c) 2018
*Created on 2018-10-28  
*Author: 十甫
*Version 1.0 
*Title: GCD
*Time: 1.5 mins
*/ 
#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;

inline int gcd(int a, int b) {
	while(b) {
		int r = a % b;
		a = b, b = r;
	}
	return a;
}
int main() {
	int n;
	scanf("%d", &n);
	while(n--) {
		int a, b;
		scanf("%d%d", &a, &b);
		printf("%d
", gcd(a, b));
	}
	return 0;
}

ex-gcd

/*Copyright: Copyright (c) 2018
*Created on 2018-10-28  
*Author: 十甫
*Version 1.0 
*Title: ex-GCD
*Time: 3.0 mins but 1 mistakes
*/
#include<iostream>
#include<cstdio>
using namespace std;

inline void exgcd(int a, int b, int &x, int &y) {
	if(!b) {
		x = 1, y = 0;
		return;
	}
	exgcd(b, a % b, y, x);
	y -= (a / b) * x;
}

int main() {
	int n;
	scanf("%d", &n);
	while(n--) {
		int a, b, x, y;
		scanf("%d%d", &a, &b);
		exgcd(a, b, x, y);
		printf("(%d * %d) + (%d * %d) = gcd(%d, %d)
", x, a, y, b, a, b);
	}
	return 0;
}