zoukankan      html  css  js  c++  java
  • hdu 2669(扩展欧几里得)

    Romantic

    Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
    Total Submission(s): 4400    Accepted Submission(s): 1852


    Problem Description
    The Sky is Sprite.
    The Birds is Fly in the Sky.
    The Wind is Wonderful.
    Blew Throw the Trees
    Trees are Shaking, Leaves are Falling.
    Lovers Walk passing, and so are You.
    ................................Write in English class by yifenfei



    Girls are clever and bright. In HDU every girl like math. Every girl like to solve math problem!
    Now tell you two nonnegative integer a and b. Find the nonnegative integer X and integer Y to satisfy X*a + Y*b = 1. If no such answer print "sorry" instead.
     
    Input
    The input contains multiple test cases.
    Each case two nonnegative integer a,b (0<a, b<=2^31)
     
    Output
    output nonnegative integer X and integer Y, if there are more answers than the X smaller one will be choosed. If no answer put "sorry" instead.
     
    Sample Input
    77 51 10 44 34 79
     
    Sample Output
    2 -3 sorry 7 -3
     
    题解:由ax+by = gcd(a,b) 当 a,b互素是才会有解。然后X要是尽量小的正数,假设我们得到的是 X0 ,在有解的情况下方程ax+by=c的通解为 {X0*(c/d)+k*b/gcd(a,b)} (k = ..-2,-1,0,1,2..)
    所以我们可以得到在最小的X为 (X0%b+b)%b.代入得Y
    #include <stdio.h>
    #include <string.h>
    #include <algorithm>
    using namespace std;
    typedef long long LL;
    
    LL extend_gcd(LL a,LL b,LL &x,LL &y){
        if(!b){
            x=1,y = 0;
            return a;
        }else{
            LL x1,y1;
            LL d = extend_gcd(b,a%b,x1,y1);
            x = y1;
            y = x1 - a/b*y1;
            return d;
        }
    }
    int main()
    {
        LL a,b,x,y;
        while(~scanf("%lld%lld",&a,&b)){
            LL d = extend_gcd(a,b,x,y);
            if(d!=1){
                printf("sorry
    ");
            }else{
                x = (x%b+b)%b;
                y = (1-a*x)/b;
                printf("%lld %lld
    ",x,y);
            }
        }
        return 0;
    }
  • 相关阅读:
    左右对齐Justify遇到的坑
    JS中的相等性判断===, ==, Object.is()
    JS调用栈的一些总结
    VueI18n
    【转】Webpack 快速上手(下)
    【转】Webpack 快速上手(中)
    【转】Webpack 快速上手(上)
    springboot打包排除指定jar包依赖
    prometheus+grafana搭建
    fbctf 安装部署出现的问题
  • 原文地址:https://www.cnblogs.com/liyinggang/p/5528236.html
Copyright © 2011-2022 走看看