92.c

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

structListNode {
intval;
structListNode*next;
};

structListNode*reverseBetween(structListNode*head, intm, intn) {
structListNode*front, *rear; /* front and rear node of reversed list */
structListNode*left, *right; /* left and right linked point */
structListNode*p, *q, *t;
front=rear=left=right=NULL;

intlen=n-m+1;
t=head;
m-=1;
while (m--) {
left=t;
t=t->next;
 }

rear=t;
p=q=NULL;
while (len--) {
q=t->next;
t->next=p;
p=t;
t=q;
 }
right=t;
front=p;

/* left to front, rear to right */
if (left) {
left->next=front;
 }
else {
head=front;
 }
rear->next=right;

returnhead;
}

intmain() {
structListNode*l1= (structListNode*)calloc(5, sizeof(structListNode));
structListNode*p=l1;

inti;
for (i=1; i <= 4; i++) {
p->val=i;
p->next=p+1;
p++;
 }
p->val=5;
p->next=NULL;

p=l1;
while (p) {
printf("%d ", p->val);
p=p->next;
 }
printf("\n");

p=reverseBetween(l1, 2, 4);
while (p) {
printf("%d ", p->val);
p=p->next;
 }
printf("\n");

structListNode*l2= (structListNode*)calloc(2, sizeof(structListNode));
l2->val=3;
l2->next=l2+1;
l2->next->val=5;
l2->next->next=NULL;

p=l2;
while (p) {
printf("%d ", p->val);
p=p->next;
 }
printf("\n");

p=reverseBetween(l2, 1, 2);
while (p) {
printf("%d ", p->val);
p=p->next;
 }
printf("\n");

return0;
}