How Effective are Technical Interviews?(jeanhsu.com)

    if (i==0) return "0";

    // allocate the right size
    strsize=0;
    if (i<0) strsize++;
    tmp=i>0?i:-i;
    while (tmp > 0) {
        strsize++;
        tmp /= 10;
    }
    res=(char *)malloc(strsize);

    // write the values
    j=strsize;
    res[j]='\0';
    if (i<0) {
        i=-i;
        res[0]= '-';
    }
    while (i != 0) {
        // printf(".%d(%c)", j, '0'+i%10);
        res[--j] = '0' + i%10;
        i/=10;
    }
    return res;
}

    str = '';
    while (i > 0 ) {
      # least significant digit
      r = i % 10;
      # throw away the least significant digit
      i = i / 10;
      case
        when r = 0 then
          str =  '0' << str
        when r == 1 then
          str =  '1' << str
        ... etc
      end
    }
    return str;

  #include <stdio.h>
  
  int main() {
  	int integer = -1231232342;
  	int negative = integer < 0 ? -1 : 1;
  	integer = integer * negative;
  	char c[11];
  	int index = 0;
  	while(integer != 0) {
  		int position = integer % 10;
  		c[index++] = 48 + position;
  		integer = integer / 10;
  	}
  	if(negative == -1)
  		c[index++] = '-';
  	int swap = 0;
  	while(swap < index / 2) {
  		char t = c[swap];
  		c[swap] = c[index - swap - 1];
  		c[index - swap++ - 1] = t;
  	}
  	printf("%s\n", c);
  	return 10;
  }