package class03; import java.util.Arrays; public class Code01_BSExist { // arr保证有序 public static boolean find(int[] arr, int num) { if (arr == null || arr.length == 0) { return false; } int L = 0; int R = arr.length - 1; while (L <= R) { int mid = (L + R) / 2; if (arr[mid] == num) { return true; } else if (arr[mid] < num) { L = mid + 1; } else { R = mid - 1; } } return false; } // for test public static boolean test(int[] sortedArr, int num) { for (int cur : sortedArr) { if (cur == num) { return true; } } return false; } // for test public static int[] generateRandomArray(int maxSize, int maxValue) { int[] arr = new int[(int) ((maxSize + 1) * Math.random())]; for (int i = 0; i < arr.length; i++) { arr[i] = (int) ((maxValue + 1) * Math.random()) - (int) (maxValue * Math.random()); } return arr; } public static void main(String[] args) { int testTime = 500000; int maxSize = 10; int maxValue = 100; boolean succeed = true; for (int i = 0; i < testTime; i++) { int[] arr = generateRandomArray(maxSize, maxValue); Arrays.sort(arr); int value = (int) ((maxValue + 1) * Math.random()) - (int) (maxValue * Math.random()); if (test(arr, value) != find(arr, value)) { System.out.println("出错了!"); succeed = false; break; } } System.out.println(succeed ? "Nice!" : "Fucking fucked!"); } }