编辑代码

#include <stdio.h>
#include <string.h>
int main () {
    char s1[] = "hello", s2[] = "world";
    char s3[50];
    int j = 0;
    for (int i = 0; i < strlen(s1); i++) {
        s3[j++] = s1[i];
    }
    for (int i = 0; i < strlen(s2); i++) {
        s3[j++] = s2[i];
    }
    s3[j] = '\0';
    printf("%s", s3);
	return 0;
}