ab壓力測試解讀
阿新 • • 發佈:2022-03-25
java常用排序演算法
氣泡排序
public static void bubble(int[] arr) { int tem; for (int i = 1; i < arr.length; ++i) { // 負輔助變數,用於提前結束 int count = 0; for (int j = 1; j < arr.length; ++j) { if (arr[j - 1] > arr[j]) { tem = arr[j]; arr[j] = arr[j - 1]; arr[j - 1] = tem; // 減少賦值判斷 if (count == 0) { ++count; } } } if (count == 0) { break; } } }
選擇排序
public static void select(int[] arr) { for (int i = 0; i < arr.length - 1; ++i) { // 找到最小值和下標 int minIndex = i; int min = arr[i]; for (int j = i + 1; j < arr.length; ++j) { if (min > arr[j]) { min = arr[j]; minIndex = j; } } // 交換 if (minIndex != i) { arr[minIndex] = arr[i]; arr[i] = min; } } }
插入排序
public static void insert(int[] arr) { for (int i = 1; i < arr.length; ++i) { int insertValue = arr[i]; int insertIndex = i - 1; while (insertIndex >= 0 && insertValue < arr[insertIndex]) { arr[insertIndex + 1] = arr[insertIndex]; --insertIndex; } arr[insertIndex + 1] = insertValue; } }
希爾排序
交換法
public static void shell01(int[] arr) {
int temp;
for (int gap = arr.length / 2; gap > 0; gap /= 2) {
for (int i = gap; i < arr.length; ++i) {
for (int j = i - gap; j >= 0; j -= gap) {
if (arr[j] > arr[j + gap]) {
temp = arr[j];
arr[j] = arr[j + gap];
arr[j + gap] = temp;
}
}
}
}
}
位移法
public static void shell02(int[] arr) {
for (int gap = arr.length / 2; gap > 0; gap /= 2) {
for (int i = gap; i < arr.length; ++i) {
// 儲存下標和值
int index = i;
int temp = arr[index];
while (index - gap >= 0 && temp < arr[index - gap]) {
// 移動
arr[index] = arr[index - gap];
index -= gap;
}
arr[index] = temp;
}
}
}