class Solution {
public:
int lengthOfLIS(vector<int>& nums) {
//我们动态的构建一个升序数组
//将原数组的逐个取出与升序数组的末尾进行比较
//如果比末尾还大,加在升序数组末尾,反之,在升序数组中找到合适的位置替换
int n = nums.size();
vector<int> dp;
//由于是跟末尾比较,初始数组必须包含一个元素
dp.push_back(nums[0]);
for(int i = 1; i < n; ++i){
//比末尾大,在升序数组末尾加入该元素
if(dp.back() < nums[i])
dp.push_back(nums[i]);
//比末尾小,对升序数组进行二分查找,找到替换的元素进行替换
else{
int left = 0, right = dp.size() - 1;
while(left <= right){
int mid = (left + right) >> 1;
//大了往右找
if(dp[mid] < nums[i]){
left = mid + 1;
}
//小了或相等往左找
else
right = mid - 1;
}
//left就是最后要替换的
dp[left] = nums[i];
}
}
return dp.size();
}
};
Accepted
54/54 cases passed (4 ms)
Your runtime beats 98.43 % of cpp submissions
Your memory usage beats 94.27 % of cpp submissions (10.1 MB)