C/code/加强训练任务/字符串转换成十进制整数.c

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

int main() {
    char str[100];
    fgets(str, 100, stdin);

    // Remove newline character
    str[strcspn(str, "\n")] = '\0';

    int is_negative = 0;
    int hex_found = 0;
    int i;
    unsigned long long decimal = 0;

    for (i = 0; str[i] != '#'; i++) {
        if (str[i] == '-') {
            is_negative = 1;
        } else if (isxdigit(str[i])) {
            hex_found = 1;
            char hex_char = toupper(str[i]);
            int hex_value = isdigit(hex_char) ? hex_char - '0' : hex_char - 'A' + 10;
            decimal = decimal * 16 + hex_value;
        }
    }

    if (is_negative) {
        decimal = -decimal;
    }

    printf("%lld\n", decimal);

    return 0;
}