编程接收到的信号SIGSEGV，在代码块中调试时出现分段错误

Question

I'm a beginner in c++ and I was trying to solve https://projecteuler.net/problem=9 . I wrote a code for it and it shows the error - Program received signal SIGSEGV, Segmentation fault. In strcmp () (C:\\Windows\\syswow64\\msvcrt.dll) while debugging.

If I straightaway run the program, a dialog box appears that says "windows is checking for a solution."

I've tried not using the string function and instead of writing pytha(a,b,c)=="true" , I just wrote axa+bxb=c*c (I wrote * instead of x but here it is not showing * between the two a's so I am replacing it with x) and the code works perfectly fine. But the thing is why does it not work with the string function?

I do not see anything wrong with the code.

I've found plenty of similar questions- 1. https://www.codeproject.com/Questions/93770/what-is-this-means-Program-received-signal-SIGSEGV
According to this one, my program is referring to a memory location which it does not have access to. But I do not see anything that is restricting this code to access something.

2. Program received signal SIGSEGV, Segmentation fault error

3. Debug---Program received signal SIGSEGV, Segmentation fault

4. program received signal SIGSEGV, segmentation fault

5. "Program received signal SIGSEGV, Segmentation fault."

6. Program received signal SIGSEGV, Segmentation fault

7. Program received signal SIGSEGV, segmentation fault, Linked list program

None of them answer my query as I am not able to relate to the codes mentioned in them to my code. The link numbered 5 mentions that probably the error is because of the large number of computations involved. Even I had that doubt for my code, but it works fine when I don't use the function "pytha". Also, I do not see the large number of steps involved related in any way to an error related to memory access.

Also, even if large number of steps are involved is the reason, the program should compile when given enough time. But it doesn't. It straightaway shows the error that "Windows is looking for a solution."

#include <cmath>
#include <iostream>
#include <string>

using namespace std;

string pytha(int a, int b, int c) {
    if(a * a + b * b == c * c) return "true";
}

int main() {
    for(int a = 1; a < 1000; a++) {
        for(int b = 1; b < 1000; b++) {
            for(int c = 1; c < 1000; c++) {
                if(a + b + c == 1000) {
                    if(pytha(a, b, c) == "true")
                        cout << "a= " << a << " b= " << b << " c= " << c;
                }
            }
        }
    }
}

Please note that this code is a very inefficient one. The point is not to solve the question but to know why is the program not compiling.

Answer 1

pytha doesn't return a value on its all control flow paths.

Fix:

string pytha(int a, int b, int c)
{
    if (a*a+b*b==c*c)
        return "true";
    return "";
}

Always compile your code with warnings enabled. For gcc and clang the compiler command line options are -Wall -Wextra -Werror .

---

You probably want to use bool type instead of string .