A1067 Sort with Swap(0, i) (18/25 分)

#include <bits/stdc++.h>
using namespace std;
/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main(int argc, char** argv) {
  
  int n;
  cin >> n;
  
  int pos[100010];
  int left = 0; //记录不在本位的个数
  int begin; //记录0开始的位置 
  
  for(int i = 0; i < n; i++){
    cin >> pos[i];
    if(pos[i] != i){
      left++;
    }else{
      pos[i] = -1;
    }
    if(pos[i] == 0){
      begin = i;
    } 
  }
//  cout << left;
//  cout << "begin:" << begin <<endl;
  
  int num = 0;
  int temp; 
  
  int k = 1;
  
  while(left>0){
//    cout << "left::::" << left << endl;
    if(begin != 0){ //0不在0位 
      for(int i = 0; i < n; i++){
        if(pos[i] == begin){
          pos[begin] = -1;
          pos[i] = 0;
          begin = i;
          num++;
          //cout << i << "  " << pos[i] << endl;
          left--;
          break;
        }
      } 
    }else{
      while(k < n){
        if(pos[k] != -1){
          temp = pos[k];
          pos[k] = pos[0];
          pos[0] = temp;
          begin = k;
          //cout << "i::::" << i << endl;
          num++;
          break;
        }
        else{
          k++;
        }
      }
    }
    
    
    
    int ii;
    for(ii = 1; ii < n; ii++){
      if(pos[ii] != -1){
        break;
      }
    }
    
//    cout << "ii:" << ii << endl;
    if(ii == n){
      cout << num;
      break;
    }
  }
  return 0;
}