2015-10-18 10:42:52 +08:00

124 lines
3.0 KiB
C++

// Source : https://oj.leetcode.com/problems/subsets-ii/
// Author : Hao Chen
// Date : 2014-07-05
/**********************************************************************************
*
* Given a collection of integers that might contain duplicates, S, return all possible subsets.
*
* Note:
*
* Elements in a subset must be in non-descending order.
* The solution set must not contain duplicate subsets.
*
* For example,
* If S = [1,2,2], a solution is:
*
* [
* [2],
* [1],
* [1,2,2],
* [2,2],
* [1,2],
* []
* ]
*
*
**********************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void getCombination(vector<int>& v, int n, int k, vector<int>& solution, vector< vector<int> >& result );
vector<vector<int> > combine(vector<int>& v, int k);
vector<vector<int> > combine1(vector<int>& v, int k);
vector<vector<int> > combine2(vector<int>& v, int k);
vector<vector<int> > subsets(vector<int> &S) {
vector<vector<int> > result;
sort(S.begin(), S.end());
for(int i=0; i<=S.size(); i++){
vector<vector<int> > r = combine(S, i);
result.insert(result.end(), r.begin(), r.end());
}
return result;
}
vector<vector<int> > combine(vector<int> &v, int k) {
vector<vector<int> > result;
vector<int> solution;
getCombination(v, v.size(), k, solution, result);
return result;
}
void getCombination(vector<int> &v, int n, int k, vector<int>& solution, vector< vector<int> >& result ){
if (k==0){
//sort to meet LeetCode requirement
vector<int> v = solution;
sort(v.begin(), v.end());
result.push_back(v);
return;
}
for(int i=n; i>0; i--){
solution.push_back(v[i-1]);
getCombination(v, i-1, k-1, solution, result);
solution.pop_back();
//skip the duplication
while (i>1 && v[i-1]==v[i-2]) i--;
}
}
void printResult(vector<vector<int> >& result)
{
for(int i=0; i<result.size(); i++){
cout << "{";
for(int j=0; j<result[i].size(); j++){
cout << " " << result[i][j];
}
cout << " }" <<endl;
}
}
void printArray(vector<int>& v){
cout << "{";
for(int i=0; i<v.size(); i++) {
cout << " " << v[i];
}
cout << " }" << endl;
}
int main(int argc, char** argv)
{
srand(time(NULL));
int n = 3;
if (argc>1){
n = atoi(argv[1]);
}
vector<int> v;
for(int i=n; i>0; i--){
v.push_back(random()%n+1);
}
printArray(v);
cout << "--------------------" <<endl;
vector<vector<int> > r = subsets(v);
printResult(r);
cout << "====================" <<endl;
int a[] = {1, 4, 4, 4, 4,};
v.clear();
v.insert(v.begin(), a, a+5);
printArray(v);
cout << "--------------------" <<endl;
r = subsets(v);
printResult(r);
cout << "====================" <<endl;
}