【题目链接】
https://www.luogu.org/problemnew/show/P1032
【算法】
【代码】
#include<bits/stdc++.h> using namespace std; int n; string A,B; string s1[30],s2[30]; map<string,bool> mp; inline bool bfs() { int i,pos; queue< pair<string,int> > q; pair<string,int> cur; string tmp; q.push(make_pair(A,0)); while (!q.empty()) { cur = q.front(); q.pop(); if (cur.second > 10) return false; if (cur.first == B) { printf("%d\n",cur.second); return true; } for (i = 1; i <= n; i++) { if (cur.first.find(s1[i]) == string :: npos) continue; pos = cur.first.find(s1[i]); while (true) { tmp = cur.first; tmp.replace(pos,s1[i].length(),s2[i]); if (!mp[tmp]) { q.push(make_pair(tmp,cur.second+1)); mp[tmp] = true; } if (cur.first.find(s1[i],pos+1) == string :: npos) break; pos = cur.first.find(s1[i],pos+1); } } } } int main() { cin >> A >> B; n = 1; while (cin >> s1[n] >> s2[n]) n++; if (!bfs()) printf("NO ANSWER!\n"); return 0; }
原文：https://www.cnblogs.com/evenbao/p/9278746.html