1 2 #include <stdio.h> 3 #include <stdlib.h> 4 5 int main ( void ) 6 { 7 char* aa = malloc(8); 8 aa[-1] = 17; 9 if (aa[-1] == 17) 10 printf("17\n"); else printf("not 17\n"); 11 return 0; 12 } 13