Mine

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

int matoi(char* lolwut) {
    int roflcopter = 0;
    int neg = 0;
    int i;
    for (i = 0; i < strlen(lolwut); ++i) {
        if (lolwut[i] == '-')
            if (i == 0)
                neg = 1;
            else
                break;
        else if (lolwut[i] <= '9' && lolwut[i] >= '0')
            roflcopter = roflcopter * 10 + lolwut[i] - '0';
        else
            break;
    }
    return (neg) ? (-1 * roflcopter) : (roflcopter);
}

int main() {
    int x = matoi("-32");
    printf("%i\n", x);
    return 0;
}