101 lines
2.2 KiB
C++
101 lines
2.2 KiB
C++
// Source : https://oj.leetcode.com/problems/permutations-ii/
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// Author : Hao Chen
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// Date : 2014-06-21
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/**********************************************************************************
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*
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* Given a collection of numbers that might contain duplicates, return all possible unique permutations.
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*
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* For example,
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* [1,1,2] have the following unique permutations:
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* [1,1,2], [1,2,1], and [2,1,1].
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*
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*
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**********************************************************************************/
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#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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#include <iostream>
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#include <vector>
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#include <algorithm>
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using namespace std;
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// To deal with the duplication number, we need do those modifications:
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// 1) sort the array [pos..n].
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// 2) skip the same number.
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vector<vector<int> > permute(vector<int> &num) {
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vector<vector<int> > vv;
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vv.push_back(num);
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if (num.size() <2){
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return vv;
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}
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int pos=0;
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while(pos<num.size()-1){
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int size = vv.size();
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for(int i=0; i<size; i++){
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//sort the array, so that the same number will be together
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sort(vv[i].begin()+pos, vv[i].end());
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//take each number to the first
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for (int j=pos+1; j<vv[i].size(); j++) {
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vector<int> v = vv[i];
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//skip the same number
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if (j>0 && v[j]==v[j-1]){
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continue;
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}
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int t = v[j];
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v[j] = v[pos];
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v[pos] = t;
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vv.push_back(v);
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}
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}
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pos++;
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}
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return vv;
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}
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void printVector( vector<int>& pt)
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{
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cout << "{ ";
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for(int j=0; j<pt.size(); j++){
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cout << pt[j] << " ";
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}
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cout << "} " << endl;
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}
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int main(int argc, char** argv)
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{
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int n = 3;
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if (argc>1){
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n = atoi(argv[1]);
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}
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srand(time(NULL));
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vector<int> v;
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for (int i=0; i<n; i++) {
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v.push_back(random()%n+1);
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}
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/*v[0] =0;
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v[1] =1;
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v[2] =0;
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v[3] =0;
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v[4] =9;*/
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printVector(v);
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cout << "-----------------" << endl;
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vector<vector<int> > vv;
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vv = permute(v);
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for(int i=0; i<vv.size(); i++) {
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printVector(vv[i]);
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}
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return 0;
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}
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