習題11-7 奇數值結點鏈表 (20分)
本題要求實現兩個函數,分別將讀入的數據存儲爲單鏈表、將鏈表中奇數值的結點重新組成一個新的鏈表。鏈表結點定義如下:
struct ListNode {
int data;
ListNode *next;
};
函數接口定義:
struct ListNode *readlist();
struct ListNode *getodd( struct ListNode **L );
函數readlist
從標準輸入讀入一系列正整數,按照讀入順序建立單鏈表。當讀到−1時表示輸入結束,函數應返回指向單鏈表頭結點的指針。
函數getodd
將單鏈表L
中奇數值的結點分離出來,重新組成一個新的鏈表。返回指向新鏈表頭結點的指針,同時將L
中存儲的地址改爲刪除了奇數值結點後的鏈表的頭結點地址(所以要傳入L
的指針)。
裁判測試程序樣例:
#include <stdio.h>
#include <stdlib.h>
struct ListNode {
int data;
struct ListNode *next;
};
struct ListNode *readlist();
struct ListNode *getodd( struct ListNode **L );
void printlist( struct ListNode *L )
{
struct ListNode *p = L;
while (p) {
printf("%d ", p->data);
p = p->next;
}
printf("\n");
}
int main()
{
struct ListNode *L, *Odd;
L = readlist();
Odd = getodd(&L);
printlist(Odd);
printlist(L);
return 0;
}
/* 你的代碼將被嵌在這裏 */
輸入樣例:
1 2 2 3 4 5 6 7 -1
輸出樣例:
1 3 5 7
2 2 4 6
#include <stdio.h>
#include <stdlib.h>
#define N 20
struct ListNode {
int data;
struct ListNode *next;
};
struct ListNode *readlist();
struct ListNode *getodd( struct ListNode **L );
void printlist( struct ListNode *L )
{
struct ListNode *p = L;
while (p) {
printf("%d ", p->data);
p = p->next;
}
printf("\n");
}
int main()
{
struct ListNode *L, *Odd;
L = readlist();
Odd = getodd(&L);
printlist(Odd);
printlist(L);
return 0;
}
struct ListNode *readlist(){
int i=0,in,n,a[N];
struct ListNode *h,*p,*q;
scanf("%d", &in);
while(in != -1){
a[i]=in;
i++;
scanf("%d", &in);
}
n=i;
/*
for(i=0;i<n;i++)
printf("%d ", a[i]);
printf("\n");
*/
h = (struct ListNode*)malloc(sizeof(struct ListNode));
h->data = a[0];
h->next = NULL;
p=q=h;
i=1;
while(i<n){
q = (struct ListNode*)malloc(sizeof(struct ListNode));
q->data = a[i];
q->next = NULL;
p->next = q;
p=q;
i++;
}
p->next=NULL;
return h;
}
struct ListNode *getodd( struct ListNode **L ){
struct ListNode *oddhead,*p,*q,*head;
int a[N],i=0,n;
head = *L;
/*先確定head->data 不是奇數*/
while(head->data%2==1){
a[i++]=head->data;
p = head->next;
free(head);
head = p;
}
q=head;
p=head->next;
while(p){
if(p->data%2==1){
a[i++]=p->data;
q->next=p->next;
free(p);
p=q->next;
continue;
}
q=p;
p=p->next;
}
*L=head;
n=i;
/*調試用
for(i=0;i<n;i++)
printf("%d ", a[i]);
printf("\n");
*/
/*重新建立奇數值的鏈表*/
oddhead = (struct ListNode*)malloc(sizeof(struct ListNode));
oddhead->data = a[0];
oddhead->next = NULL;
p=q=oddhead;
i=1;
while(i<n){
q = (struct ListNode*)malloc(sizeof(struct ListNode));
q->data = a[i];
q->next = NULL;
p->next = q;
p=q;
i++;
}
p->next=NULL;
return oddhead;
}