usaa24/a1/program.c

#include <stdio.h>
#include <string.h>

#define MAX_LENGTH 100

int isMatchingPair(char open, char close)
{
    return (open == '(' && close == ')') || (open == '{' && close == '}') || (open == '[' && close == ']') || (open == '<' && close == '>');
}

int main()
{
    char input[MAX_LENGTH];
    fgets(input, sizeof(input), stdin);
    
    int len = strlen(input);
    if (input[len - 1] == '\n')
    {
        input[len - 1] = '\0';
        len--;
    }

    printf("Read: %s\n", input);

    char stack[MAX_LENGTH];

    int top = -1;

    for (int i = 0; i < len; i++)
    {
        char ch = input[i];
        if (ch == '(' || ch == '{' || ch == '[' || ch == '<')
        {
            stack[++top] = ch;
        }
        else if (ch == ')' || ch == '}' || ch == ']' || ch == '>')
        {
            if (top == -1)
            {
                printf("Unexpected closing bracket %c in %d\n", ch, i);
                return 0;
            }
            else if (!isMatchingPair(stack[top], ch))
            {
                printf("Crossed bracket %c in %d, expected %c\n", ch, i, (stack[top] == '(' ? ')' : stack[top] == '{' ? '}' : stack[top] == '[' ? ']' : '>'));
                return 0;
            }
            top--;
        }
    }

    if (top != -1)
    {
        memset(input, 0, len);
        sprintf(input,"Missing closing brackets: ");
        len = strlen(input);
        for (int i = top; i >= 0; i--)
        {
            input[len++] = (stack[i] == '(' ? ')' : stack[i] == '{' ? '}' : stack[i] == '[' ? ']' : '>');
        }
        input[len] = 0;
        printf("%s\n", input);
        return 0;
    }

    printf("All brackets OK\n");
    return 0;
}