C프로그래밍질문 : 미치겠음.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
int main(void)
{
    int i;
    int j=0;
    unsigned int node1_la=0;
    char buf2_1[40];
    char buf3_1[4][4];
    strcpy(buf2_1,"0000000000000000000012345678.");
 
    for(i = 0; i < 9; i++){
        if(buf2_1[20+i] != '.'){
            printf("%c", buf2_1[20+i]);
            buf3_1[j][i] = buf2_1[20+i];
        }
        continue;
    }
    printf("\n");
    printf("%s\n",buf3_1[j]);
    node1_la = atol(buf3_1[j]);
    printf("%d\n",node1_la);
 
    return 0;
}