stack+DFS ZOJ 1004 Anagrams by Stack

 

题目传送门

 1 /*  2  stack 容器的应用： 要求字典序升序输出，所以先搜索入栈的  3  然后逐个判断是否满足答案，若不满足，回溯继续搜索，输出所有符合的结果  4 */  5 #include <cstdio>  6 #include <iostream>  7 #include <algorithm>  8 #include <stack>  9 #include <cmath> 10 #include <cstring> 11 #include <vector> 12 using namespace std; 13 14 const int MAXN = 1e4 + 10; 15 const int INF = 0x3f3f3f3f; 16 17 string s1, s2; 18 int len; 19 stack<char> S; 20 vector<char> V; 21 22 void DFS(int push, int pop) 23 { 24 if (push == len && pop == len) 25  { 26 for (int i=0; i<V.size (); ++i) 27 cout << V[i] << " "; 28 cout << endl; 29  } 30 31 if (push + 1 <= len) //入栈 32  { 33  S.push (s1[push]); 34 V.push_back ('i'); 35 DFS (push+1, pop); 36  S.pop (); 37  V.pop_back (); 38  } 39 40 if (pop + 1 <= push && pop + 1 <= len && S.top () == s2[pop]) //出栈 41  { 42 char ch = S.top (); 43  S.pop (); 44 V.push_back ('o'); 45 DFS (push, pop+1); 46  S.push (ch); 47  V.pop_back (); 48  } 49 } 50 51 int main(void) //ZOJ 1004 Anagrams by Stack 52 { 53 //freopen ("ZOJ_1004.in", "r", stdin); 54 55 while (cin >> s1 >> s2) 56  { 57  V.clear (); 58 while (!S.empty ()) S.pop (); 59 60 len = s1.length (); 61 62 cout << "[" << endl; 63 DFS (0, 0); 64 cout << "]" << endl; 65  } 66 67 return 0; 68 } 69 70 /* 71 [ 72 i i i i o o o i o o 73 i i i i o o o o i o 74 i i o i o i o i o o 75 i i o i o i o o i o 76 ] 77 [ 78 i o i i i o o i i o o o 79 i o i i i o o o i o i o 80 i o i o i o i i i o o o 81 i o i o i o i o i o i o 82 ] 83 [ 84 ] 85 [ 86 i i o i o i o o 87 ] 88 */