题解 | #全排列#

bug：第21行为res[u] = str[i];原来写的是res[i] = str[i];

另解：可用next_permutation解决

#include<iostream>
#include<cstring>
using namespace std;

const int N = 30;

string str;
char res[N];
bool st[N];

void f(int u){
	
	int len = str.size();
	if(u == len){
		cout<<res<<endl;
		return;
	}
	
	for(int i = 0;i < len;i++){
		if(st[i] != 1){
			res[u] = str[i];
			st[i] = 1;
			
			f(u + 1);
			
			st[i] = 0;//回溯 
		}
	}
	
}

int main(){
    
    cin>>str;
	f(0);
    
    return 0;
}