Codeforces Round #249 (Div. 2) A. Black Square

水题

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main(){
	vector<int> a(4);
	cin >> a[0] >> a[1]>>a[2]>>a[3];
	string str;
	cin >> str;
	int res = 0;
	for(int i = 0 ; i < str.length(); ++ i) res+=a[str[i]-'0'-1];
	cout<<res<<endl;

}