【算法】程序猿不写代码是不对的73

package com.kingdz.algorithm.time201706;import java.util.Arrays;/** * <pre> * 步骤问题 *  * http://judgecode.com/problems/1006 *  * Suppose you start from x = 0. * In each step you can operate on x by either of the 2 operations: * (1) x = x * 2 * (2) x = x + 1 * Given an integer n. How many operations at least to change x into n? *  * Input:A single non-negative integer n which is no larger than 2147483647. * Output:The minimum number of operations to change x = 0 into n. * </pre> *  * @author kingdz *  */public class Algo22 {    public static void main(String[] args) {        int n = 100;        int[] arr = new int[n + 1];        arr[0] = 1;        for (int i = 0; i < arr.length; i++) {            int now = arr[i];            int a = i * 2;            int b = i + 1;            if (a < arr.length && arr[a] == 0) {                arr[a] = now + 1;            }            if (b < arr.length && arr[b] == 0) {                arr[b] = now + 1;            }            if (a == n || b == n) {                break;            }        }        System.out.println(arr[n] - 1);        System.out.println(Arrays.toString(arr));    }}