有没有oop高手，实在是黔驴技穷了

一开始用oop写，输出有问题而且不好改，模仿思路写了个简洁点的c，还是WA

#include <iostream>
#include <string>
#include <math.h>
using namespace std;
int len(int n) {
    if (n == 0) {
        return 1;
    }
    int count = 0;
    if (n < 0) {
        count++;
    }
    while (n) {
        count++;
        n /= 10;
    }
    return count;
}
int transform(string s) {
    int ans = 0;
    for(int i=0;i<=s.length()-1;i++){
        ans+=(int)(pow(10,i))*(s[s.length()-1-i]-'0') ; 

    }
    return ans;
}
int main() {
    string a[55][5];
    int b[55][5];
    int n;
    cin >> n;
    char mark;
    for (int i = 1; i <= n; i++) {
        string s;
        cin >> s;
        if (isalpha(s[0])) {
            mark = s[0];
            b[i][1] = mark - '0';
            for (int j = 1; j <= 2; j++) {
                cin >> a[i][j];
                b[i][j + 1] = transform(a[i][j]);
            }
        } else {
            b[i][1] = mark - '0';
            a[i][1] = s;
            b[i][2] = transform(s);
            cin >> a[i][2];
            b[i][3] = transform(a[i][2]);
        }
    }
    for (int i = 1; i <= n; i++) {
        if (b[i][1] == '+' - '0') {
            cout << b[i][2] << "+" << b[i][3] << "=" << b[i][2] + b[i][3] << endl;
            cout << len(b[i][2]) + b[i][3] + len(b[i][2] + b[i][3]) + 2 << endl;
        }
        if (b[i][1] == '-' - '0') {
            cout << b[i][2] << "-" << b[i][3] << "=" << b[i][2] - b[i][3] << endl;
            cout << len(b[i][2]) + len(b[i][3]) + len(b[i][2] - b[i][3]) + 2 << endl;
        }
        if (b[i][1] == '*' - '0') {
            cout << b[i][2] << "*" << b[i][3] << "=" << b[i][2]*b[i][3] << endl;
            cout << len(b[i][2]) + b[i][3] + len(b[i][2]*b[i][3]) + 2 << endl;
        }
    }
    return 0;
}

输出只有一个return 0,不知道cout的内容给谁吞了 问了chatgpt，隔靴挠痒 please check other bug There are a few issues with the modified code:

In the len function, when n is negative, you are not handling the - sign correctly. You need to remove the sign before counting the number of digits. Change count++; to n = abs(n); count++; to fix this.

In the main function, you are not initializing the mark variable. You need to move the cin >> s; line outside the if-else block and assign the first character of s to mark.

In the first if block of the for loop, you are using j <= 2 instead of j < 2. This will cause the loop to run 3 times instead of 2, resulting in undefined behavior.

In the len function, you are not accounting for the additional characters (+, -, *) and = that will be printed. You need to add 4 to the total length.