1 #include <iostream> 2 #include <cmath> 3 #include <string> 4 #include <cstring> 5 #include <algorithm> 6 #include <map> 7 using namespace std; 8 9 char s[50]; 10 11 bool cmp(char x,char y){ 12 return x < y; 13 } 14 15 int main(){ 16 cin >> s; 17 int len = strlen(s); 18 sort(s, s+len, cmp); 19 //cout << s<< endl; 20 do{ 21 cout<<s<< endl; 22 } 23 while(next_permutation(s,s+len)); 24 return 0; 25 }
回溯：
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 using namespace std; 6 char s[20]; 7 int book[30],a[20],ans[20],n; 8 9 void dfs(int dis,int cnt) 10 { 11 int i,j; 12 if(cnt==n) { 13 for(i=1;i<=n;i++) cout<<ans[i]; 14 cout<<endl; 15 return; 16 } 17 for(i=dis;i<n;i++) { 18 if(book[i]==0) { 19 book[i]=1; 20 ans[cnt+1]=a[i]; 21 dfs(dis,cnt+1); 22 book[i]=0; 23 while(i<n && a[i]==a[i+1]) i++; 24 } 25 } 26 27 } 28 29 30 int main() 31 { 32 ios::sync_with_stdio(false); 33 int i,j; 34 cin>>s; 35 n=strlen(s); 36 for(i=0;i<n;i++) a[i]=s[i]-'0'; 37 sort(a,a+n); 38 dfs(0,0); 39 return 0; 40 }