usaa24/a1/program.c

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

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

char expected_closing(char open) {
    if (open == '{') return '}';
    if (open == '[') return ']';
    if (open == '(') return ')';
    if (open == '<') return '>';
    return '\0';
}

void check_brackets(const char *code) {
    char stack[100];
    int top = -1;

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

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

    if (top == -1) {
        printf("All brackets OK\n");
    } else {
        printf("Missing closing brackets: ");
        while (top >= 0) {
            printf("%c", expected_closing(stack[top--]));
        }
        printf("\n");
    }
}

int main() {
    char code[100];
    if (fgets(code, sizeof(code), stdin) != NULL) {
        
        size_t len = strlen(code);
        if (len > 0 && code[len - 1] == '\n') {
            code[len - 1] = '\0';
        }
        check_brackets(code);
    }
    return 0;
}