数字转化成字符串C语言

#include <stdio.h>
void Myitoa(int,char *);
int getnumberLength(int);
int main(){
    char buf[];
    int i = ;
    Myitoa(i, buf);
    printf("%s", buf);

    getchar();
    return ;

}
void Myitoa(int a, char *p){
    int numberlength = getnumberLength(a);
    int flag = ;
    if (a<){
        flag = -;
        a = -a;
    }
    *(p + numberlength) = ;
    while (numberlength-- > ){
        p[numberlength] = a %  + 0x30;
        a = a / ;
    }
    if (flag < ){
        p[] = (char);
    }
}
int getnumberLength(int a){
    int result = ;
    if (a < ){
        a = -a;
        result ++;
    }
    while (a /= ){
        result++;
    }
    return result;
}