OJ-Problems-Source/HDOJ/4192_autoAC.cpp
2016-09-04 14:28:52 +08:00

94 lines
2.1 KiB
C++

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
#define N 10005
char str[N];
int num[N];
char op[N];
int v[11];
int id[11];
char cmp(char a,char b){
if(a=='+'){
if(b=='+' || b=='-' || b==')')return '>';
else return '<';
}
if(a=='-'){
if(b=='+' || b=='-' || b==')')return '>';
else return '<';
}
if(a=='*'){
if(b=='(')return '<';
else return '>';
}
if(a=='('){
if(b==')')return '=';
else return '<';
}
if(a==')'){
return '>';
}
}
int cal(int a,int b,char c){
if(c=='+')return a+b;
if(c=='-')return a-b;
if(c=='*')return a*b;
}
int gao(){
int i,j;
int topnum = 0,topop = 1;
int k = 1;
op[1] = '(';
for(i=1;str[i];i++){
if(islower(str[i])){
topnum++;
num[topnum] = v[id[k++]];
} else {
char c = cmp(op[topop],str[i]);
char tag;
if(c=='<'){
topop++;
op[topop] = str[i];
} else if(c=='='){
topop--;
} else if(c=='>'){
int b = num[topnum--];
int a = num[topnum--];
tag = op[topop--];
int res = cal(a,b,tag);
topnum++;
num[topnum] = res;
i--;
}
}
}
return num[topnum];
}
int main(){
int n;
while(scanf("%d",&n) && n){
int i,j;
for(i=1;i<=n;i++){
scanf("%d",&v[i]);
id[i] = i;
}
int ans;
scanf("%d",&ans);
scanf("%s",str+1);
int len = strlen(str+1);
str[0] = '(',str[len+1] = ')',str[len+2] = '\0';
bool ok =0;
do{
int tmp = gao();
if(tmp==ans){
ok = 1;
break;
}
}while(next_permutation(id+1,id+1+n));
if(ok)puts("YES");
else puts("NO");
}
return 0;
}