POJ1635 Subway tree systems ——（判断树的同构，树的最小表示法）

 1 #include <stdio.h>
 2 #include <algorithm>
 3 #include <string.h>
 4 #include <string>
 5 #include <iostream>
 6 #include <vector>
 7 using namespace std;
 8 
 9 string str1, str2;
10 
11 string min_pre(string str){
12       vector<string> box;
13       string ret = "";
14       int equal = 0, st = 0;
15       for(int i = 0; i < str.size(); i++){
16            if(str[i] == ‘0‘) equal++;
17            else equal--;
18            if(equal == 0){
19                 if(i - 1 > st + 1){
20                     box.push_back("0" + min_pre(str.substr(st + 1,i - 1 - st)) + "1");
21                 }else box.push_back("01");
22                 st = i + 1;
23            }
24       }
25       sort(box.begin(), box.end());
26       for(int i = 0; i < box.size(); i++) ret += box[i];
27       return ret;
28 }
29 
30 int main(){
31       int ca;
32       scanf("%d", &ca);
33       while(cin >> str1 >> str2){
34            if(min_pre(str1) == min_pre(str2)) printf("same\n");
35            else printf("different\n");
36       }
37 }