一些常见的基础算法(未完待续)
快速排序int partition(int left,int right,int arr[]){ int i = left; int j = right; int value = arr[left]; while (j > i) { //从右边j开始找到一个比value小的值 while (j > i && arr[j] >= value) j--; if (j > i) { arr[i] = arr[j]; i++; } //从左边i开始找到一个比value大的值 while (j > i && arr[i] i) { arr[j] = arr[i]; j--; } } //i=j时代表所有比value大的值都到了右边，比value小的到了左边 arr[i] = value; return i;}
void quicksort(int arr[], int left, int right){ if (left
堆排序include //假设第i个节点的左右子树已经是最大堆，加入第//i个节点后重新调整堆void heapadjust(int arr[], int i, int size){ int l = 2*i; int r = l+1; int max = i; if(iarr[max]) max = l; if(rarr[max]) max = r; if(max!=i){ arr[max] ^= arr[i]; arr[i] ^= arr[max]; arr[max] ^= arr[i]; //int temp = arr[i]; //arr[i] = arr[max]; //arr[max] = temp; heapadjust(arr, max, size); } }}//建立最大堆void buildheap(int arr[], int heapsize){ int middle = heapsize/2; for(int i=middle;i>=1;i--) heapadjust(arr,i,heapsize);}//堆排序void heapsort(int arr[], int size){ buildheap(arr,size); for(int i=size;i>=2;i--){ //arr[i] ^= arr[1]; //arr[1] ^= arr[i]; //arr[i] ^= arr[1]; arr[i] += arr[1]; arr[1] = arr[i]-arr[1]; arr[i] = arr[i]-arr[1]; heapadjust(arr,1,i-1); }}void printarr(int arr[], int n){ int i = -1; while(i++
插入排序void insertsort(){ int arr[10] = { 1, 34, 5, 6, 8, 12, 5, 9, 345, 0 }; int n = 10; cout = 0 && arr[j] > temp; j--) { arr[j + 1] = arr[j]; } //最后将最初的arr[i]值放到空出的位置 arr[j + 1] = temp; } for (int i = 0; i
选择排序void selectsort(){ int arr[10] = { 1, 34, 5, 6, 8, 12, 5, 9, 345, 0 }; int n = 10; cout
按层打印二叉树#include queue q = new queue();void printbinarytree(node *n){ q.put(n); node *next = null; while(null!=(next=q.get())) { if(next->val!=null) std::coutvalue; if(next->left!=null) q.put(next->left); if(next->right!=null) q.put(next->right); }}
后序遍历二叉树void postorder(node root){ if(root == null) return; postorder(root->left); postorder(root->right); visit(root);}void postorder(node root){ stack stack = new stack(); node tmp = root; while(tmp!=null || !stack.empty()) { if(tmp!=null) { stack.push(tmp,left); tmp = tmp->left; } else { s = stack.pop(); tmp = s.tmp; tag = s.tag; if(tag==right) { visit(tmp); tmp = null; } else { stack.push(tmp,right); tmp = tmp->right; } } }}
单链表相关(待完善)//单链表反转void reverse1(node **head){ node *temp; node *op; temp = *head; op = temp->next; (*head)->next = null; while(op) { //保存原始op的下一个 temp = op->next; //拆开链表 op->next = *head; //移动head *head = op; //移动op op = temp; }}void reverse2(node **head){ //使用栈先进后出}//反向打印单链表void reverseprint(node *head){ if (head->next != null) { reverseprint(head->next); printf(%d\n,head->next->data); }}
数组去重function cleanarray(arr){ var hash = {}; var len = arr.length; for (var i = 0; i
求字符数组全排列function permute(strpre, str){ if(str.length==0){ console.log(strpre); }else{ var l = str.length; for(var i=0;i
二分查找int binarysearch(int arr[], int l, int r, int k){ while(lk) r = m+1; else l = m-1; } return -1;}int binarysearch1(int arr[], int l, int r, int k){ if(r>=l){ int m = l+(r-l)/2; if(arr[m]==k) return m; if(arr[m]>k) binarysearch1(arr, l, m-1, k); else binarysearch1(arr, m+1, r, k); } return -1;}
字符串反转#include #include void reverse1(char *s){ char *p1,*p2; char c; p1 = s; p2 = s+strlen(s)-1; while(p11){ char c = *s; *s = *(s+tail-1); *(s+tail-1) = c; reverse4(s+1,tail-2); }}
字符串复制void copy(char *s, char *d){ while(*s!='\0'){ *d++ = *s++; } *d = '\0';}
以上就介绍了常见基础算法笔记，包括了方面的内容，希望对php教程有兴趣的朋友有所帮助。