24
04/2015
[LeetCode] Remove Duplicates from Sorted Array
Remove Duplicates from Sorted Array
Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.
Do not allocate extra space for another array, you must do this in place with constant memory.
For example,
Given input array A = [1,1,2],
Your function should return length = 2, and A is now [1,2].
解题思路：
双指针，记录新数组的长度和老数组当前扫描的位置，若不相同，则添加到新数组中。
class Solution {
public:
int removeDuplicates(int A[], int n) {
if(n==0 || n==1){
return n;
}
int newN=1;
for(int i=1; i<n; i++){
if(A[i]!=A[newN-1]){
A[newN]=A[i];
newN++;
}
}
return newN;
}
};二次刷题（update in 2015-07-30）
第二次刷数组变成了vector，其实是一样的。
class Solution {
public:
int removeDuplicates(vector<int>& nums) {
int len = nums.size();
if(len<=1){
return len;
}
int newLen = 1;
for(int i=1; i<len; i++){
if(nums[i]!=nums[newLen-1]){
nums[newLen] = nums[i];
newLen++;
}
}
return newLen;
}
};
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