关于#c++#的问题：字符串数据貌似溢出缓冲区

Question

string动态字符串数据貌似溢出缓冲区，在网上未能查阅到相关资料，求解答与订正。
问题

#include<bits/stdc++.h>
using namespace std;
int same_num(string x, char y)
{
    int num = 0;
    for (int i = 0; i < x.length(); i++)
    {
        if (x[i] == y)
        {
            num++;
        }
    }
    return num;
}
int solve_p(string X,char Y)
{
    string* xx = new string[same_num(X, Y)]();
    for (int i = 0; i < same_num(X, Y); i++)
    {
        xx[i] = Y;//报错处
    }
    int px;
    stringstream Px;
    Px << xx;
    Px >> px;
    return px;
}
int main()
{
    string A, B;
    char a, b;
    cin >> A >> a >> B >> b;
    cout << same_num(A, a) << " "<<same_num(B, b);
    cout << solve_p(A, a)<<" "<< solve_p(B, b);
    return 0;
}

报错：

能正常运行但每次输入数据所得结果都为随机数。

Answer 1

xx不应该用string *，应该用char *
另外，不要重复调用same_num函数，会降低你的程序效率。
char * xx 动态申请空间时，需要多少申请一个char，用来设置字符串结束符。
代码修改后的运行结果：

代码修改如下：

#include<bits/stdc++.h>
using namespace std;
int same_num(string x, char y)
{
    int num = 0;
    for (int i = 0; i < x.length(); i++)
    {
        if (x[i] == y)
        {
            num++;
        }
    }
    return num;
}
int solve_p(string X, char Y)
{
    unsigned int size = same_num(X, Y);
    char* xx = new char[size+1];
    xx[size] = 0;
    for (int i = 0; i < size; i++)
    {
        xx[i] = Y;//报错处
    }
    int px;
    stringstream Px;
    Px << xx;
    Px >> px;
    return px;
}
int main()
{
    string A, B;
    char a, b;
    cin >> A >> a >> B >> b;
    cout << same_num(A, a) << " " << same_num(B, b) << endl;
    cout << solve_p(A, a) << " " << solve_p(B, b) << endl;
    cout << solve_p(A, a) + solve_p(B, b) << endl;
    return 0;
}