leetcode

Algorithm I: Day 2

2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/ Problems/0189.cpp b/ Problems/0189.cpp

@@ -1,12 +1,22 @@

// O(n) memory solution

class Solution { public: void rotate(vector<int> &nums, int k) { k %= nums.size(); vector<int> t(k); for (int i = 0; i < k; i++) t[i] = nums[nums.size() - k + i];

for (int i = nums.size() - k - 1; i >= 0; i--) nums[i + k] = nums[i];

for (int i = 0; i < k; i++) nums[i] = t[i]; } };

// O(1) memory solution

class Solution {

public:

void rotate(vector<int> &nums, int k) {

k %= nums.size();

reverse(nums.begin(), nums.end());

reverse(nums.begin(), nums.begin() + k);

reverse(nums.begin() + k, nums.end());

}

};

diff --git a/ Problems/0977.cpp b/ Problems/0977.cpp

@@ -1,3 +1,4 @@

// Intuitive solution

class Solution { public: vector<int> sortedSquares(vector<int> &nums) {

@@ -18,3 +19,17 @@ public: return res; } };

// Intuitive solution, better execution

// avoids recomputation of squares

// avoids reversal of the array

class Solution {

public:

vector<int> sortedSquares(vector<int>& nums) {

int n = nums.size(), i=0, j =nums.size()-1;

vector<int> res(n);

for_each(nums.begin(), nums.end(), [](int &a) { a*=a; });

while(i<=j) res[--n] = nums[i]>nums[j] ? nums[i++] : nums[j--];

return res;

}

};