c语言常用算法整理

代码如下：

//交换 void swap(int *a, int *b){ 
    int tmp=*a; *a=*b; *b=tmp; } //查找最小 int min(int x, int y) { 
    return x < y ? x : y; } typedef struct _Range { 
    int start, end; } Range; Range new_Range(int s, int e) { 
    Range r; r.start = s; r.end = e; return r; } //冒泡排序 void looperSort(int *arr, int len){ 
    int i,j; for (i = 0; i < len - 1; ++i) { 
    for (j = 0; j < len - 1-i; ++j) { 
    if (arr[j]>arr[j+1]){ 
    swap(&arr[j], &arr[j+1]); } } } } //选择排序 void selectSort(int *arr, int num){ 
    int min, i, j; for (i = 0; i < num - 1; ++i) { 
    min=i; for (j = i+1; j < num; ++j) { 
    if (arr[j]<arr[min]){ 
    min=j; } } if (min!=i) swap(&arr[min], &arr[i]); } } //插入排序 void insertSort(int *arr, int num){ 
    int i,j, tmp; for (i = 1; i < num; ++i) { 
    tmp=arr[i]; for (j = i; j > 0 && arr[j-1] > tmp; --j) { 
    arr[j]=arr[j-1]; } arr[j]=tmp; } } //希尔排序 void shellSort(int *arr, int num) { 
    int gap, i, j, temp; for (gap = num >> 1; gap > 0; gap = gap >>= 1) for (i = gap; i < num; i++) { 
    temp = arr[i]; for (j = i - gap; j >= 0 && arr[j] > temp; j -= gap){ 
    arr[j + gap] = arr[j]; } arr[j + gap] = temp; } } //归并排序 void mergeSort(int *arr, int num) { 
    int* a = arr; int* b = (int*) malloc(num * sizeof(int)); int seg, start; for (seg = 1; seg < num; seg += seg) { 
    for (start = 0; start < num; start += seg + seg) { 
    int low = start, mid = min(start + seg, num), high = min(start + seg + seg, num); int k = low; int start1 = low, end1 = mid; int start2 = mid, end2 = high; while (start1 < end1 && start2 < end2){ 
    b[k++] = a[start1] < a[start2] ? a[start1++] : a[start2++]; } while (start1 < end1){ 
    b[k++] = a[start1++]; } while (start2 < end2){ 
    b[k++] = a[start2++]; } } int* temp = a; a = b; b = temp; } if (a != arr) { 
    int i; for (i = 0; i < num; i++) b[i] = a[i]; b = a; } free(b); } void merge_sort_recursive(int arr[], int reg[], int start, int end) { 
    if (start >= end) return; int len = end - start, mid = (len >> 1) + start; int start1 = start, end1 = mid; int start2 = mid + 1, end2 = end; merge_sort_recursive(arr, reg, start1, end1); merge_sort_recursive(arr, reg, start2, end2); int k = start; while (start1 <= end1 && start2 <= end2) reg[k++] = arr[start1] < arr[start2] ? arr[start1++] : arr[start2++]; while (start1 <= end1) reg[k++] = arr[start1++]; while (start2 <= end2) reg[k++] = arr[start2++]; for (k = start; k <= end; k++) arr[k] = reg[k]; } //归并排序 递归 void mergeSort2(int *arr, const int len) { 
    int reg[len]; merge_sort_recursive(arr, reg, 0, len - 1); } //快速排序 void quickSort(int *arr, const int num) { 
    if (num <= 0) return; // 避免len等於負值時引發段錯誤（Segment Fault） // r[]模擬列表,p為數量,r[p++]為push,r[--p]為pop且取得元素 Range r[num]; int p = 0; r[p++] = new_Range(0, num - 1); while (p) { 
    Range range = r[--p]; if (range.start >= range.end) continue; int mid = arr[(range.start + range.end) / 2]; // 選取中間點為基準點 int left = range.start, right = range.end; do { 
    while (arr[left] < mid) ++left; // 檢測基準點左側是否符合要求 while (arr[right] > mid) --right; //檢測基準點右側是否符合要求 if (left <= right) { 
    swap(&arr[left],&arr[right]); left++;right--; // 移動指針以繼續 } } while (left <= right); if (range.start < right) r[p++] = new_Range(range.start, right); if (range.end > left) r[p++] = new_Range(left, range.end); } } void quick_sort_recursive(int arr[], int start, int end) { 
    if (start >= end) return; int mid = arr[end]; int left = start, right = end - 1; while (left < right) { 
    while (arr[left] < mid && left < right) left++; while (arr[right] >= mid && left < right) right--; swap(&arr[left], &arr[right]); } if (arr[left] >= arr[end]) swap(&arr[left], &arr[end]); else left++; if (left) quick_sort_recursive(arr, start, left - 1); quick_sort_recursive(arr, left + 1, end); } //快速排序 递归 void quickSort2(int *arr, int len) { 
    quick_sort_recursive(arr, 0, len - 1); } //二分查找 int halfSearch(int key, int *a, int n) //自定义函数binary_search() { 
    int start=0; int end=n-1; while (start<=end){ 
    int middle=(start+end)/2; if (key<a[middle]){ 
    end=middle-1; } else if (key>a[middle]){ 
    start=middle+1; } else{ 
    return middle; } } return -1; } //查找重复 void searchRepeat(int *arr, int num, int searchKey){ 
    for (int i = 0; i < num; ++i) { 
    for (int j = i+1; j < num; ++j) { 
    if (arr[i]==arr[j]){ 
    LOGI("repeat num index:%d", i); break; } } } } 

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