Merge Sorted Array 合并两个有序数组 @LeetCode

来源：互联网发布：绝食减肥知乎编辑：程序博客网时间：2024/05/17 23:10

题目：

合并两个有序数组

思路：

两个指针merge，注意从尾到头merge

package Level2;import java.util.Arrays;/** * Merge Sorted Array *  *  Given two sorted integer arrays A and B, merge B into A as one sorted array.Note:You may assume that A has enough space to hold additional elements from B. The number of elements initialized in A and B are m and n respectively. * */public class S88 {public static void main(String[] args) {int[] A = {1,2,3,0,0,0,0};int[] B = {4,5,6,0,0,0};merge(A, 3, B, 3);System.out.println(Arrays.toString(A));}// 合并两个有序数组，从尾到头合并public static void merge(int A[], int m, int B[], int n) {        int i = m-1, j = n-1;// i指向A的有效末尾，j指向B的有效末尾        int k = m+n-1;// k指向合并后A的末尾                // 当两个数组都有数时，比较合并        while(i>=0 && j>=0){        if(A[i] >= B[j]){        A[k] = A[i];        i--;        }else{        A[k] = B[j];        j--;        }        k--;        }                // 如果有其中一个数组剩下，就直接合并        while(i >= 0){        A[k] = A[i];        i--;        k--;        }        while(j >= 0){        A[k] = B[j];        j--;        k--;        }            }}

public class Solution {    public void merge(int A[], int m, int B[], int n) {        int k = m+n-1;        int i = m-1;        int j = n-1;        while(k >= 0){            if(i < 0){                A[k] = B[j];                j--;                k--;                continue;            }            if(j < 0){                A[k] = A[i];                i--;                k--;                continue;            }            if(A[i] >= B[j]){                A[k] = A[i];                i--;            }else{                A[k] = B[j];                j--;            }            k--;        }    }}