Clang++ compiled successfully but executable file didn't run - c++

Question

I ran into this problem when solving a math problem. Here's the code:
// program to check if parentheses expression is correct
// {()}[{()}] = true, ()(} = false
#include <string.h>
#include <iostream>
#include <stack>
using namespace std;
int par(string str) {
int a = str.length();
stack<char> S;
char x;
for (int i = 0; i < a; i++) {
x = str[i];
if (x == '(' || x == '[' || x == '{') {
S.push(x);
} else {
if (x == ')') {
if (S.top() == '(') {
S.pop();
} else
return 0;
} else if (x == ']') {
if (S.top() == '[') {
S.pop();
} else
return 0;
} else if (x == '}') {
if (S.top() == '{') {
S.pop();
} else
return 0;
}
}
}
if (!S.empty()) {
return 0;
} else
return 1;
}
int main() {
int n;
string str;
cin >> n;
for (int i = 0; i < n; i++) {
cin >> str;
cout << par(str) << endl;
}
return 0;
}
Ignore the bad coding, when compile this code using this command:
clang++ -std=c++20 -Wall -Wextra -pedantic -g par.cpp -o par.exe
The code compiled, executable generated, but when I open par.exe it terminates immediately.
But when using g++, it worked well:
g++ -std=c++20 -Wall -Wextra -pedantic -g par.cpp -o par.exe
Here's the clang++ version:
>clang++ --version
clang version 15.0.5
Target: x86_64-w64-windows-gnu
Thread model: posix
InstalledDir: C:/msys64/ucrt64/bin
and g++:
>g++ --version
g++.exe (tdm64-1) 10.3.0
Copyright (C) 2020 Free Software Foundation, Inc.
I'm assumimg this was because of the <stack> and <queue> library, as I used clang without these libraries and it worked well.
Any ideas ?