[LeetCode]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.

思考：3指针。从后往前遍历。

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

2014-03-27 16:53:19

class Solution {
public:
void merge(int A[], int m, int B[], int n) {
int i=m-1;
int j=n-1;
int k=m+n-1;
while(i>=0&&j>=0)
{
if(A[i]>B[j]) A[k--]=A[i--];
else A[k--]=B[j--];
}
//未考虑m=0的情况
while(j>=0) A[k--]=B[j--];
}
};