88. Merge Sorted Array

Given two sorted integer arraysnums1andnums2, mergenums2intonums1as one sorted array.

Note:
You may assume thatnums1has enough space (size that is greater or equal tom+n) to hold additional elements fromnums2. The number of elements initialized innums1andnums2aremandnrespectively.

解题方法

從屁股到後面

//思路：從屁股到前面
    public void merge(int[] A, int m, int[] B, int n) {
        int i = m-1, j = n-1, index = m + n - 1;
        while (i >= 0 && j >= 0) {
            if (A[i] > B[j]) {
                A[index--] = A[i--];
            } else {
                A[index--] = B[j--];
            }
        }
        while (i >= 0) {
            A[index--] = A[i--];
        }
        while (j >= 0) {
            A[index--] = B[j--];
        }
    }