[置顶] 从二级指针看华为和迅雷两道小题

原题：http://blog.csdn.net/v_july_v/article/details/11921021

1. 华为

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

/*
 * HuaWei: A string compressed example
 * */
void stringZip(const char *pInputStr, char *pOutputStr) {
    int len = strlen(pInputStr);
    char *tmp = (char *)malloc(sizeof(len * sizeof(char)));
    int start = 0;
    int end = start + 1;
    int cnt = 0;
    int i = 0;

    while(pInputStr[start]) {
	if(pInputStr[start] == pInputStr[end]) {
	    cnt++;
	    end++;
	}
	else {
	    if(cnt == 0)  tmp[i++] = pInputStr[start];
	    else if(cnt > 0) {
		tmp[i++] = cnt + 1 + '0';
		tmp[i++] = pInputStr[start];
		cnt = 0;
	    }
	    start = end;
	    end = start + 1;
	}
    }
    tmp[i] = '';
    strncpy(pOutputStr, tmp, strlen(tmp));
    free(tmp);
}
void main() {  
    char str[1024];  
    char compress_str[1024];
    printf("Input a string:");
    gets(str);  
    stringZip(str, compress_str);
    printf("The compressed string is:");
    puts(compress_str);
}  

2. 迅雷

#include <stdio.h>
#include <stdlib.h>
/*
 * XunLei: difference of linked list
 * */
typedef struct node {
    int elem;
    struct node *next;
}node;

void create(node **head, int n) {
    int elem;
    int i;
    node *p;
    node *r;
    for(i = 0;i < n;i++) {
	if(scanf("%d", &elem) != 1) {
	    perror("input error!
");
	    exit(1);
	}
	p = (node *)malloc(sizeof(node *));
	if(!p) {
	    perror("memory error!
");
	    exit(2);
	}
	p->elem = elem;
	p->next = 0;
	if(!*head) *head = p;
	else {
	    r->next = p;
	}
	r = p;
    }
}
void show(node *head) {
    node *p = head;
    while(p) {
	printf("%d
", p->elem);
	p = p->next;
    }
}
void difference(node **LA, node *LB) {
    node *p, *q, *pre;
    node *head;
    p = *LA;
    pre = *LA;
    head = p;
    while(p) {
	q = LB;
	while(q) {
	    if(p->elem == q->elem) break;
	    q = q->next;
	}
	if(q) {
	    if(pre == p) {
		p = p->next;
		pre->next = 0;
		free(pre);
		pre = p;
		head = p;
	    }
	    else {
		pre->next = p->next;
		p->next = 0;
		free(p);
		p = pre->next;
	    }
	}
	else {
	    pre = p;
	    p = p->next;
	}
    }
    *LA = head;
}
void main() {
    node *head1 = NULL, *head2 = NULL;
    create(&head1, 5);
    printf("----------
");
    create(&head2, 3);
    difference(&head1, head2);
    printf("----------
");
    show(head1);
}