标签:数组元素 案例 tla else 查找算法 循环 ast 移动 数组下标
package cn.imooc.java2; public class Test02 { //定义一个静态方法 static int binarySerach(int[] array, int key) { //定义数组下标的最左 int left = 0; //定义数组下标的最右(下标都是从0开始的,因此需要-1) int right = array.length - 1; while (left <= right) { int mid = (left + right) / 2; //判断中间值是否为目标值 if (array[mid] == key) { return mid; } else if (array[mid] < key) { left = mid + 1; } else { right = mid - 1; } } return -1; } //测试,目标值为7 public static void main(String[] args) { Test02 s = new Test02(); int[] b={1,5,6,7,8,9,10,12}; System.out.println(s.binarySerach(b, 7)); } }
package cn.imooc.java2; public class Test02 { // 查找第一个相等的元素 static int findFirstEqual(int[] array, int key) { int left = 0; int right = array.length - 1; while (left <= right) { int mid = (left + right) / 2; if (array[mid] >= key) { right = mid - 1; } else { left = mid + 1; } } if (left < array.length && array[left] == key) { return left; } return -1; } public static void main(String[] args) { Test02 s = new Test02(); int[] b={1,5,6,7,7,7,7,8,9,10,12}; System.out.println(s.findFirstEqual(b, 7)); } }
package cn.imooc.java2; public class Test02 { static int findLastEqual(int[] array, int key) { int left = 0; int right = array.length - 1; while (left <= right) { int mid = (left + right) / 2; if (array[mid] <= key) { left = mid + 1; } else { right = mid - 1; } } if (right >= 0 && array[right] == key) { return right; } return -1; } public static void main(String[] args) { Test02 s = new Test02(); int[] b={1,5,6,7,7,7,7,8,9,10,12}; System.out.println(s.findLastEqual(b, 7)); } }
package cn.imooc.java2; public class Test02 { static int findLastEqualSmaller(int[] array, int key) { int left = 0; int right = array.length - 1; while (left <= right) { int mid = (left + right) / 2; if (array[mid] > key) { right = mid - 1; } else { left = mid + 1; } } return right; } public static void main(String[] args) { Test02 s = new Test02(); int[] b={1,5,6,7,7,7,7,8,9,10,12}; System.out.println(s.findLastEqualSmaller(b, 11)); } }
package cn.imooc.java2; public class Test02 { static int findFirstEqualLarger(int[] array, int key) { int left = 0; int right = array.length - 1; while (left <= right) { int mid = (left + right) / 2; if (array[mid] >= key) { right = mid - 1; } else { left = mid + 1; } } return left; } public static void main(String[] args) { Test02 s = new Test02(); int[] b={1,5,6,7,7,7,7,8,9,10,12}; System.out.println(s.findFirstEqualLarger(b, 11)); } }
package cn.imooc.java2; public class Test02 { static int findFirstLarger(int[] array, int key) { int left = 0; int right = array.length - 1; while (left <= right) { int mid = (left + right) / 2; if (array[mid] > key) { right = mid - 1; } else { left = mid + 1; } } return left; } public static void main(String[] args) { Test02 s = new Test02(); int[] b={1,5,6,7,7,7,7,8,9,10,12}; System.out.println(s.findFirstLarger(b, 11)); } }
标签:数组元素 案例 tla else 查找算法 循环 ast 移动 数组下标
原文地址:http://www.cnblogs.com/fengxiongZz/p/7615520.html