Uva11925

题目链接

原题的意思是把有序序列变成目标序列,例如例题中要把[1,2,3]变成[2，1，3]，我们可以采用逆向思维，就是把给出的序列变成有序序列。操作1不变，操作2变成把尾部的元素添加到头部，打印的时候逆序打印。

#include <iostream>  #include <cstring>#include <cstdio>#include <algorithm>#include <string>#include <string.h>#include <cmath>#include <sstream>#include <set>#include <map>#include <functional>#include <queue>#include <vector>using namespace std;const int maxn = 310;int n;int arr[maxn];vector<int> vec;bool judge()//判断是否顺序{    for (int i = 0; i < n - 1; i++)        if (arr[i] > arr[i + 1])            return false;    return true;}int main(){    while (scanf("%d", &n) && n != 0)    {        vec.clear();        for (int i = 0; i < n; i++)            scanf("%d", &arr[i]);        while (1)        {            if (judge())                break;            if (arr[0] != n&&arr[0] > arr[1])            {                vec.push_back(1);                swap(arr[0], arr[1]);            }            else            {                int temp = arr[n - 1];                for (int i = n - 1; i >= 0; i--)                    arr[i] = arr[i - 1];                arr[0] = temp;                vec.push_back(2);            }        }        for (int i = vec.size() - 1; i >= 0; i--)            cout << vec[i];        cout << endl;    }}