zoukankan      html  css  js  c++  java
  • Codeforces Round #277.5 (Div. 2)A——SwapSort

    A. SwapSort
    time limit per test
    1 second
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    In this problem your goal is to sort an array consisting of n integers in at most n swaps. For the given array find the sequence of swaps that makes the array sorted in the non-descending order. Swaps are performed consecutively, one after another.

    Note that in this problem you do not have to minimize the number of swaps — your task is to find any sequence that is no longer than n.

    Input

    The first line of the input contains integer n (1 ≤ n ≤ 3000) — the number of array elements. The second line contains elements of array: a0, a1, ..., an - 1 ( - 109 ≤ ai ≤ 109), where ai is the i-th element of the array. The elements are numerated from 0 to n - 1 from left to right. Some integers may appear in the array more than once.

    Output

    In the first line print k (0 ≤ k ≤ n) — the number of swaps. Next k lines must contain the descriptions of the k swaps, one per line. Each swap should be printed as a pair of integers i, j (0 ≤ i, j ≤ n - 1), representing the swap of elements ai and aj. You can print indices in the pairs in any order. The swaps are performed in the order they appear in the output, from the first to the last. It is allowed to print i = j and swap the same pair of elements multiple times.

    If there are multiple answers, print any of them. It is guaranteed that at least one answer exists.

    Sample test(s)
    Input
    5
    5 2 5 1 4
    
    Output
    2
    0 3
    4 2
    
    Input
    6
    10 20 20 40 60 60
    
    Output
    0
    
    Input
    2
    101 100
    
    Output
    1
    0 1
    

            排个序,然后和排序前对照,不一样就往后找到应该在这一位上的数,然后交换


    #include <map>
    #include <set>
    #include <list>
    #include <queue>
    #include <stack>
    #include <vector>
    #include <cmath>
    #include <cstdio>
    #include <cstring>
    #include <iostream>
    #include <algorithm>
    
    using namespace std;
    
    int a[3030];
    int b[3030];
    
    struct node
    {
    	int x, y;
    }pp[3030];
    
    int main()
    {
    	int n;
    	while (~scanf("%d", &n))
    	{
    		int cnt = 0;
    		for (int i = 0; i < n; ++i)
    		{
    			scanf("%d", &a[i]);
    			b[i] = a[i];
    		}
    		sort(b, b + n);
    		int x, y;
    		for (int i = 0; i < n; ++i)
    		{
    			if (a[i] == b[i])
    			{
    				continue;
    			}
    			x = i;
    			for (int j = i + 1; j < n; ++j)
    			{
    				if (a[j] == b[i])
    				{
    					y = j;
    					break;
    				}
    			}
    			++cnt;
    			pp[cnt].x = x;
    			pp[cnt].y = y;
    			a[x] ^= a[y];
    			a[y] ^= a[x];
    			a[x] ^= a[y];
    		}
    		printf("%d
    ", cnt);
    		for (int i = 1; i <= cnt; ++i)
    		{
    			printf("%d %d
    ", pp[i].x, pp[i].y);
    		}
    	}
    	return 0;
    }


    版权声明:本文博主原创文章,博客,未经同意不得转载。

  • 相关阅读:
    实数---Currency讲解
    自己写的 限制文本框TEdit中只能输入数字
    maven增加自定义jar包
    delphi 类方法、类变量、类常量、类属性的研究,自己的研究
    BASE64 官方方法,我自己用的,注意记住换行问题。
    ComponentCount 与 ControlCount 区别
    关于delphi 中 Sender的学习
    Redis源码分析(二十八)--- object创建和释放redisObject对象
    Redis源码分析(二十八)--- object创建和释放redisObject对象
    Redis源码分析(二十九)--- bio后台I/O服务的实现
  • 原文地址:https://www.cnblogs.com/zfyouxi/p/4810709.html
Copyright © 2011-2022 走看看