C中的流程树层次结构

我正在尝试创建一个进程树层次结构,它为树高h创建C子级。我已经编写了以下代码,但每个进程只创建一个子级。我哪里出错了?

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

void createProcess(int height,int children){
    int root, parent, t1, t2, t3, i, pid, status; 

    root = getpid();
    parent = getppid();
    printf("%d: Process starting\n", root);
    printf("%d: Parent's id = %d\n", root, parent);
    printf("%d: Height in the tree = %d\n", root, height);
    printf("%d: Creating %d children at height %d\n", root, children, height - 1);

    char c[4], h[4];
    sprintf(h, "%d", height - 1);
    sprintf(c, "%d", children);

    char *args[] = {"./forkk", h, c, NULL}; 
    for (i = 0; i < children; i++) {
        t1 = fork();
        if (t1 != 0) {
            printf("child pid %d    parent pid %d\n", getpid(), getppid());
            break;
        }
        if (t1 == 0) {
            execvp("./forkk", args);
        }
    }
    pid = wait(&status);
    sleep(5);
    //printf("%d Terminating at Height %d\n",root,height);
}

int main(int argc, char** argv) {
    int i;

    printf("No of Arguments: %d\n", argc);
    for (i = 0; i < argc; i++) {
        printf("%s\n", argv[i]);
    }
    int height = atoi(argv[1]);
    int children = atoi(argv[2]);
    printf("Height  %d\n", height);
    printf("Children  %d\n", children);
    if (height > 1)
        createProcess(height, children);
    return 0;
}