帮我排错 #include <iostream> #include <stack> #include <cstring> using namespace std; int n; int solve(string s) { stack<int> st; char sign = '+'; int num = 0; int ans = 0; for(int i = 0; i < s.size(); i++) { if(s[i] == ' ') { continue; } if(s[i] >= '0' && s[i] <= '9') { num = num*10+(s[i]-'0'); } if(s[i] == '+' || s[i] == '-' || s[i] == '*' || s[i] == '/' || i == s.size()-1) { if(sign == '+') { st.push(num); } if(sign == '-') { st.push(-num); } if(sign == '*') { st.top() *= num; } if(sign == '/') { st.top() *= num; } sign = s[i]; num = 0; } } while (!st.empty()) { ans += st.top(); st.pop(); } return ans; } int main() { string s; getline(cin, s); cout << solve(s) << endl; return 0; }

在计算除法时，代码中写成了 `st.top() *= num`，实际应该是 `st.top() /= num`。

修改后的代码如下所示：

#include <iostream>
#include <stack>
#include <cstring>
using namespace std;

int n;

int solve(string s) {
    stack<int> st;
    char sign = '+';
    int num = 0;
    int ans = 0;
    for(int i = 0; i < s.size(); i++) {
        if(s[i] == ' ') {
            continue;
        }
        if(s[i] >= '0' && s[i] <= '9') {
            num = num*10+(s[i]-'0');
        }
        if(s[i] == '+' || s[i] == '-' || s[i] == '*' || s[i] == '/' || i == s.size()-1) {
            if(sign == '+') {
                st.push(num);
            }
            if(sign == '-') {
                st.push(-num);
            }
            if(sign == '*') {
                st.top() *= num;
            }
            if(sign == '/') {
                st.top() /= num; // 修改这一行
            }
            sign = s[i];
            num = 0;
        }
    }
    while (!st.empty()) {
        ans += st.top();
        st.pop();
    }
    return ans;
}

int main() {
    string s;
    getline(cin, s);
    cout << solve(s) << endl;
    return 0;
}