#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 105,M=30, INF = 0x3f3f3f3f, MOD = 1E9 + 7;
int a[N][M]; // 如果看不懂下面的vector 写法可以使用这个
void solve() {
    int n, m;
    cin >> n >> m;
   // vector<vector<int> > a(n + 5, vector<int>(m + 5));
    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            cin >> a[i][j];
    string s;
    cin >> s;
    int ans = 0, x = 0, y = 0;
    for (int i = 1; i < s.size(); i++) {
        if (isalpha(s[i])) {
            y = s[i] - 'A';
        } else if (isdigit(s[i]) || i == s.size() - 1) {
            x = x * 10 + s[i] - '0';
        }
        if (s[i] == '+' || i == s.size() - 1) {
            // 输出调试
            // cout << char(x + 'A') << y << " " << a[x - 1][y] << endl;
            ans += a[x - 1][y];
            x = 0;
        }
    }
    cout << ans << endl;
}
int main(int argc, char* argv[]) {
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}

• 本题是个模拟，在调试中可以输出数据进行验证，这样不容易出错。

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 105,M=30, INF = 0x3f3f3f3f, MOD = 1E9 + 7;
//int a[N][M]; // 如果看不懂下面的vector 写法可以使用这个
void solve() {
    int n, m;
    cin >> n >> m;
    vector<vector<int> > a(n + 5, vector<int>(m + 5));
    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            cin >> a[i][j];
    string s;
    cin >> s;
    int ans = 0, x = 0, y = 0;
    for (int i = 1; i < s.size(); i++) {
        if (isalpha(s[i])) {
            y = s[i] - 'A';
        } else if (isdigit(s[i]) || i == s.size() - 1) {
            x = x * 10 + s[i] - '0';
        }
        if (s[i] == '+' || i == s.size() - 1) {
            // 输出调试
            // cout << char(x + 'A') << y << " " << a[x - 1][y] << endl;
            ans += a[x - 1][y];
            x = 0;
        }
    }
    cout << ans << endl;
}
int main(int argc, char* argv[]) {
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}