反转单链表_字符串_数字
没啥太多技巧,反转就好了。单链表的时候要注意,while中不能将pCur的next指向NULL,否则的话,pNext的next就白指了。
#include "stdafx.h" #include <iostream> #include<cstring> #include <vector> #include <assert.h> using namespace std; struct ListNode { int m_key; ListNode* next; }; void createList(ListNode* &pHead) { pHead = new ListNode; pHead->m_key= 0; pHead->next = NULL; ListNode* p = pHead; for(int i=1; i<10; i++) { ListNode* pNewNode = new ListNode; pNewNode->m_key = i; pNewNode->next = NULL; p->next = pNewNode; p = pNewNode; } } void destoryList(ListNode* pHead) { assert(pHead!=NULL); ListNode* pNext = pHead->next; while(pNext != NULL) { delete pHead; pHead = pNext; pNext = pHead->next; } delete pHead; pHead = NULL; return; } ListNode* reverseList(ListNode* pHead) { assert(pHead!=NULL); if(pHead->next == NULL) return pHead; ListNode* pNext = pHead->next; ListNode* pCur = pHead; pCur->next = NULL; while (pNext!=NULL) { ListNode* pTemp = pNext->next; pNext->next = pCur; pCur = pNext; pNext = pTemp; } return pCur; } void reverseString(char* pStr) { assert(pStr!=NULL); int length = strlen(pStr); if(length == 0) return; char* pBegin = pStr,*pEnd = pStr+length-1; while(pBegin<pEnd) { char temp = *pBegin; *pBegin = *pEnd; *pEnd = temp; pBegin++; pEnd--; } } int reverseInt(int num) { int reverseNum = 0; while (num!=0) { int res = num%10; reverseNum = reverseNum * 10 +res; num /= 10; } return reverseNum; } int main() { // 反转单链表 ListNode* head = NULL; createList(head); head = reverseList(head); ListNode* p = head; while(p) { cout<<p->m_key<<" "; p=p->next; } cout<<endl; destoryList(head); // 反转字符串 char* str = "0123456789"; char* pStr = (char*)malloc((strlen(str)+1)*sizeof(char)); strcpy(pStr,str); reverseString(pStr); cout<<pStr<<endl; // 反转数字 int n = 123456789; cout<<reverseInt(n)<<endl; }
输出的结果:
9 8 7 6 5 4 3 2 1 0
9876543210
987654321