LeetCode078 Subsets

详细见：leetcode.com/problems/subsets

Java Solution: github

package leetcode;/* * Given a set of distinct integers, nums, return all possible subsets.Note: The solution set must not contain duplicate subsets.For example,If nums = [1,2,3], a solution is:[  [3],  [1],  [2],  [1,2,3],  [1,3],  [2,3],  [1,2],  []] */import java.util.ArrayList;import java.util.Iterator;import java.util.LinkedList;import java.util.List;public class P078_Subsets {public static void main(String[] args) {List<List<Integer>> ans = new Solution().subsets(new int[] {3, 2, 1, 0});Iterator<List<Integer>> it = ans.iterator();while (it.hasNext()) {tools.Utils.B_打印List_Integer_OneLine(it.next());}}/* * 比上题逻辑要好得多 * AC * 2 ms */static class Solution {List<List<Integer>> ans = new LinkedList<List<Integer>>();int[] ks = null;    public List<List<Integer>> subsets(int[] nums) {    ks = new int[nums.length];    for (int list_size = 0; list_size <= nums.length; list_size ++)    search(nums, list_size, 0, -1);        return ans;    }private void search(int[] nums, int list_size, int li, int maxi) {if (li == list_size) {List<Integer> temp = new ArrayList<Integer>(list_size);for (int i = 0; i != list_size; i ++)temp.add(ks[i]);ans.add(temp);return;}for (int i = maxi + 1; i < nums.length; i ++) {ks[li ++] = nums[i];search(nums, list_size, li, i);li --;}}}}

C Solution: github

/*    url: leetcode.com/problems/subsets/    AC 3ms 47.37%*/#include <stdio.h>#include <stdlib.h>typedef int* T;typedef struct al sal;typedef struct al * pal;struct al {    int capacity;    int size;    T* arr;};pal al_init(int capacity) {    pal l = (pal) malloc(sizeof(sal));    if (capacity < 1) return NULL;    l->arr = (T*) malloc(sizeof(T) * capacity);    l->capacity = capacity;    l->size = 0;    return l;}void al_expand_capacity(pal l) {    T* new_arr = (T*) malloc(sizeof(T) * (l->capacity * 2 + 1));    int i = 0;    for (i = 0; i < l->capacity; i ++)        new_arr[i] = l->arr[i];    free(l->arr);    l->arr = new_arr;    l->capacity = l->capacity * 2 + 1;}void al_add_last(pal l, T v) {    if (l->capacity == l->size) al_expand_capacity(l);    l->arr[l->size] = v;    l->size ++;}T* al_convert_to_array_free_l(pal l) {    T* arr = l->arr;    free(l);    return arr;}int* arr_copy(int* save, int n) {    int* copy = (int*) malloc(sizeof(int) * n);    int i = 0;    for (i = 0; i < n; i ++)        copy[i] = save[i];    return copy;}//[l, r]int _partition(int* n, int l, int r) {    int s = *(n + l);    while (l < r) {        while (l < r && *(n + r) >= s) r --;        *(n + l) = *(n + r);        while (l < r && *(n + l) <= s) l ++;        *(n + r) = *(n + l);    }    *(n + l) = s;    return l;}//[l, r)void _quick_sort(int* n, int l, int r) {    int p = 0;    if (l < r) {        p = _partition(n, l, r - 1);        _quick_sort(n, l, p);        _quick_sort(n, p + 1, r);    }}void search(int* n, int ni, int nn, int* save, int si, int sn, pal l, pal ln) {    int* t = NULL;    int i = 0;    if (si == sn) {        al_add_last(l, arr_copy(save, sn));        t = (int*) malloc(sizeof(int));        t[0] = sn;        al_add_last(ln, t);        return;    }    for (i = ni; i < nn; i ++) {        if (i != 0 && n[i-1] == n[i]) continue;        save[si] = n[i];        search(n, i+1, nn, save, si+1, sn, l, ln);    }}int** subsets(int* n, int nn, int** cn, int* rn) {    int ni = 0;    int* save = (int*) malloc(sizeof(int) * nn);    int sn = 0;    pal l = al_init(16);    pal ln = al_init(16);    _quick_sort(n, 0, nn);    for (sn = 0; sn <= nn; sn ++) {        search(n, 0, nn, save, 0, sn, l, ln);    }    *cn = (int*) malloc(sizeof(int) * ln->size);    *rn = ln->size;    for (ni = 0; ni < ln->size; ni ++) {        (*cn)[ni] = ln->arr[ni][0];    }    return al_convert_to_array_free_l(l);}int main() {    int n[] = {1, 2, 3};    int nn = 3;    int* cn = NULL;    int rn = 0;    int** ans = subsets(n, nn, &cn, &rn);    printf("size is %d\r\n", rn);}

Python Solution: github

#coding=utf-8'''    url: leetcode.com/problems/subsets    @author:     zxwtry    @email:      [e-mail]    @date:       2017年4月18日    @details:    Solution: 59ms 49.62%'''class Solution(object):    def search(self, n, ni, nn, s, si, sn, a):        if si == sn:            a.append(list(s))            return        for i in range(ni, nn):            if i != 0 and n[i]==n[i-1]: continue            s[si] = n[i]            self.search(n, i+1, nn, s, si+1, sn, a)            def subsets(self, n):        """        :type n: List[int]        :rtype: List[List[int]]        """        if n == None or len(n) == 0: return []        n.sort(key=None, reverse=False)        a, nn = [], len(n)        for i in range(nn+1):            s = [0] * i            self.search(n, 0, nn, s, 0, i, a)        return aif __name__ == "__main__":    n = [1 ,2, 3]    print(Solution().subsets(n))