POJ 1026

还是置换的基本概念.

有点要注意下,就是循环次数可能非常高,所以不能纯模拟,先mod一下,再处理.

#include<iostream>
#include<cstdio>
#include<vector>
#define MAXN 204
using namespace std;
char data[MAXN];
char result[MAXN];
int num[MAXN];
vector<vector<int> > qun;

void ini(int n)
{
  bool vis[MAXN] = {false};
  for (int i(1); i<=n; ++i) {
    if (!vis[i]) {
      vector<int> zq;
      zq.push_back(i);
      vis[i] = true;
      int temp = i;
      while (!vis[num[temp]]) {
        temp = num[temp];
        vis[temp] = true;
        zq.push_back(temp);  
      }
      qun.push_back(zq);  
    }  
  }  
}

void deal(int n)
{
  for (int i(0); i<qun.size(); ++i) {
    const int size = qun[i].size();
    for (int j((size - n%size)%size),cnt(0); cnt<size; ++cnt,j = (j+1)%size) {
      result[qun[i][cnt] - 1] = data[qun[i][j]];  
    }  
  } 
}

int main()
{
  int t,n,m;
  int cnt = 0;
  while (scanf("%d",&t) && t) {
    for (int i(1); i<=t; ++i) {
      scanf("%d",&num[i]);  
    }
    ini(t);      
    while (scanf("%d",&n) && n) {
      getchar();
      int i(1);
      for (; (data[i] = getchar()) != '\n'; ++i){}
      for (;i<=t; ++i)data[i] = ' ';
      deal(n);
      for (int i(0); i<t; ++i)printf("%c",result[i]);
      printf("\n");  
    }
    printf("\n");
    qun.clear();
  }
  return 0;  
}