求助RE，本地调试无内存错误

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

char *getlinex(void)
{
    //getchar();
    char * x = malloc(sizeof(char) * 1000);
    char c;
    int t = 0;
    while((c = getchar()) != EOF && c != '\n')
    {
        x[t] = c;
        t++;
    }
    x[t] = 0;
    return x;
}

int main(void)
{
    int n;
    scanf("%d",&n);
    getchar();
    char *str0 = getlinex();
    int c = 0;
    char *comm [n];
    char *topr [n + 1];
    topr[0] = str0;
    while(c < n)
    {
        comm[c] = getlinex();
        c++;
    }
    c = 0;
    int cs = 1;
    while(c < n)
    {
        if(comm[c][0] == '1')
        {
            int tom = strlen(comm[c]) - 2;
            int len = strlen(topr[cs - 1]) + tom + 1;
            topr[cs] = malloc(len * sizeof(char));
            sprintf(topr[cs],"%s%s",topr[cs - 1],comm[c] + 2);
            //printf("%s",topr[c]);
        }
        if(comm[c][0] == '2')
        {
            int start,end;
            sscanf(comm[c],"%*d %d %d",&start,&end);
            topr[cs] = malloc(end * sizeof(char) + 1);
            int c2 = start;
            int c3 = 0;
            while(c2 - start != 5)
            {
                topr[cs][c3] = topr[cs - 1][c2];
                c3++;
                c2++;
            }
            topr[cs][c3] = 0;
        }
        if(comm[c][0] == '3')
        {
            char tc[400];
            int start;
            sscanf(comm[c],"%*d %d %s",&start,tc);
            int c2 = 0;
            int c3 = start;
            topr[cs] = malloc(sizeof(char) * (strlen(topr[cs - 1]) + strlen(tc) + 2));
            while(c2 != c3)
            {
                topr[cs][c2] = topr[cs - 1][c2];
                c2++;
            }
            int c4 = 0;
            while(c4 < strlen(tc))
            {
                topr[cs][c2] = tc[c4];
                c2++;
                c4++;
            }
            while(topr[cs - 1][c3] != 0)
            {
                topr[cs][c2] = topr[cs - 1][c3];
                c2++;
                c3++;
            }
            topr[cs][c2] = 0;
        }
        if(comm[c][0] == '4')
        {
            char *tmpstr = comm[c] + 2;
            char * res = strstr(topr[cs - 1],tmpstr);
            topr[cs] = malloc(sizeof(char) * 10);
            sprintf(topr[cs],"%d",res != NULL ? res - topr[cs - 1] : -1);
        }
        c++;
        cs++;
    }
    free(str0);
    c = 0;
    while(c < n)
    {
        printf("%s\n",topr[c + 1]);
        free(comm[c]);
        free(topr[c + 1]);
        c++;
    }
}

在本地用valgrind反复检查，也没找到哪里的指针有问题