delete pics to save space

p.CH2908.cpp

@@ -0,0 +1,64 @@
+//http://contest-hunter.org:83/contest/0x29%E3%80%8C%E6%90%9C%E7%B4%A2%E3%80%8D%E7%BB%83%E4%B9%A0/2908%20%E5%AD%97%E4%B8%B2%E5%8F%98%E6%8D%A2
+#include<cstdio>
+#include<algorithm>
+#include<cstring>
+#include<cstdlib>
+#include<set>
+#include<string>
+using namespace std;
+char a[25],b[25],u[10][25],v[10][25];
+int lim,cg,lu[10],lv[10];
+set<string> st;
+void dfs(int d)
+{
+	if(d==lim)
+	{
+		if(strcmp(a,b)==0)
+		{
+			printf("%d\n",lim);
+			exit(0);
+		}
+		return;
+	}
+	if(st.find(a)!=st.end()) return;
+	st.insert(a);
+	char bk[25];
+	for(int i=0;i<cg;i++)
+	{
+		int p=0,lena=strlen(a);
+		while(p<lena)
+		{
+			int x=strstr(a+p,u[i])-a;
+			if(x<0||x>=lena) break;
+			memcpy(bk,a,sizeof(a));
+			memcpy(a+x,v[i],lv[i]);
+			memcpy(a+x+lv[i],bk+x+lu[i],lena-x-lu[i]);
+			a[lena-lu[i]+lv[i]]=0;
+			dfs(d+1);
+			memcpy(a,bk,sizeof(bk));
+			p=x+lu[i];
+		}
+	}
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%s%s",a,b);
+	while(scanf("%s%s",u[cg],v[cg])==2)
+	{
+		lu[cg]=strlen(u[cg]);
+		lv[cg]=strlen(v[cg]);
+		cg++;
+	}
+	if(strcmp(a,b)==0) { puts("0"); return 0; }
+	for(int i=1;i<=10;i++)
+	{
+		lim=i;
+		st.clear();
+		dfs(0);
+	}
+	puts("NO ANSWER!");
+	return 0;
+}