字符串的排列

字符串的排列

题目描述

输入一个字符串,按字典序打印出该字符串中字符的所有排列。例如输入字符串abc,则打印出由字符a,b,c所能排列出来的所有字符串abc,acb,bac,bca,cab和cba。

输入描述: 输入一个字符串,长度不超过9(可能有字符重复),字符只包括大小写字母。

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class Solution {
public:
    vector<string> vt;
    set<string> my_set;
    
    void Permutation(string str, unsigned int begin) {
        if (begin == str.size()) {
            my_set.insert(str);
            return;
        }
        for (unsigned int i = begin; i < str.size(); i++) {
            char temp = str[i];
            str[i] = str[begin];
            str[begin] = temp;
            
           // vt.push_back(str);
            
            Permutation(str, begin+1);
            
            temp = str[i];
            str[i] = str[begin];
            str[begin] = temp;
        }
    }
    
    vector<string> Permutation(string str) {
        if (0 == str.size()) {
            return vt;
        }
        
        Permutation(str, 0);
        for (set<string>::iterator it = my_set.begin(); it != my_set.end(); it++) {
            vt.push_back(*it);
        }
        return vt;
    }
};

class Solution {
public:
    vector<string>  vt;
    
    void Permutation(string str, unsigned int begin) {
        if (begin == str.length()) {
            vt.push_back(str);
            return;
        }
        for (unsigned int i = begin; i != str.size(); i++) {
            if (i != begin && str[i] == str[begin])
                continue;
            swap(str[i], str[begin]);
            
            Permutation(str, begin+1);
            
            swap(str[i], str[begin]);
        }
    }
    
    vector<string> Permutation(string str) {
        if (0 == str.size()) {
            return vt;
        }
        Permutation(str, 0);
        sort(vt.begin(),vt.end());
        return vt;
    }
};