两种算法:
1.原始数据是乱序的
2.原始数据是有序的
1.
1 package test; 2 3 import java.io.File; 4 5 public class Test { 6 /** 7 * 假设原始数据是乱序 8 */ 9 static int[] src = new int[] { 25, 68, 5, 38, 2, 15, 90, 55, 46 }; 10 /** 11 * 目标值 12 */ 13 static int x = 555; 14 15 public static void main(String[] args) { 16 System.out.println(getApproximate(x, src)); 17 } 18 19 /** 20 * 获取接近值 21 * 22 * @param x 23 * @param src 24 * @return 25 */ 26 private static int getApproximate(int x, int[] src) { 27 if (src == null) { 28 return -1; 29 } 30 if (src.length == 1) { 31 return src[0]; 32 } 33 int minDifference = Math.abs(src[0] - x); 34 int minIndex = 0; 35 for (int i = 1; i < src.length; i++) { 36 int temp = Math.abs(src[i] - x); 37 if (temp < minDifference) { 38 minIndex = i; 39 minDifference = temp; 40 } 41 } 42 return src[minIndex]; 43 } 44 }
运行结果:I/System.out: 90
2.
package test; import java.io.File; public class CopyOfTest { /** * 假设原始数据是有序 */ static int[] src = new int[] { 10, 12, 21, 22, 25, 30, 34, 37, 39, 46, 51, 56, 70, 85 }; /** * 目标值 */ static int x = 55; public static void main(String[] args) { System.out.println(getApproximate(x, src)); } /** * 获取接近值 * * @param x * @param src * @return */ private static int getApproximate(int x, int[] src) { if (src == null) { return -1; } if (src.length == 1) { return src[0]; } int index = -1; for (int i = 0; i < src.length; i++) { if (src[i] > x) { index = i; break; } else if (src[i] == x) { return x; } } if (index == -1) { return src[src.length - 1]; } else if (index == 0) { return src[0]; } else { return x - src[index - 1] < src[index] - x ? src[index - 1] : src[index]; } } }
运行结果:I/System.out: 56
时间: 2024-10-18 04:06:06