C Improve _day03_ play to multi-level pointer

#include <stdlib.h>#include<string.h>#include<stdio.h>Char**GETMEM51 (intnum) {    inti =0; Char**P2 =NULL; P2= (Char**)malloc(sizeof(Char*) *num); if(P2 = =NULL) {        returnNULL; }     for(i=0; i<num; i++) {P2[i]= (Char*)malloc(sizeof(Char)  * -);//Char buf[100];sprintf (P2[i],"%d%d%d", i+1, i+1, i+1); }    returnp2;}intGETMEM52 (CharP3,intnum) {    inti =0; Char**tmp =NULL; if(P3 = = NULL)//Judge P3 rather than *p3. The memory space that the P3 points to can be null    {        return-1; } tmp= (Char**)malloc(sizeof(Char*) *num); if(TMP = =NULL) {        returnNULL; }     for(i=0; i<num; i++) {Tmp[i]= (Char*)malloc(sizeof(Char)  * -);//Char buf[100];sprintf (Tmp[i],"%d%d%d", i+1, i+1, i+1); }    *P3 =tmp; //1 2    return 0;}voidGetmem52_free (CharP3,intnum) {    inti =0; Char**tmp =NULL; if(P3 = =NULL) {        return ; } tmp= *P3;  for(i=0; i<num; i++)    {         Free(Tmp[i]); }     Free(TMP); *P3 = NULL;//assign a value of an argument to null}voidMain () {inti =0, j =0; Char**P2 =NULL; intnum =5; //P2 = getMem51 (num);getMem52 (&p2, num);  for(i=0; i<num; i++) {printf ("%s \ n", P2[i]); } getmem52_free (&p2, num); printf ("hello...\n"); System ("Pause"); return ;}

C Improve _day03_ play to multi-level pointer