###### tags: `Weekly Contest`
# Weekly Contest 430

## [3402. Minimum Operations to Make Columns Strictly Increasing](https://leetcode.com/problems/minimum-operations-to-make-columns-strictly-increasing/) (<font color=#00B8A3>Easy</font>)

### Solution
要使每一列嚴格遞增，我們需要確保每列中的元素從上到下依次增大。所以我們可以計算每列中需要修改的元素數量，使其符合嚴格遞增的要求。

#### 時間複雜度:
$O(N^2)$

#### 空間複雜度:
$O(N)$

程式碼:

class Solution {
public:
    int minimumOperations(vector<vector<int>>& grid) {
        vector<int> record(grid[0].size());
        int result = 0;
        for (int i = 0; i < grid[0].size(); i++) {
            record[i] = grid[0][i];
        }
        for (int i = 1; i < grid.size(); i++) {
            for (int j = 0; j < grid[i].size(); j++) {
                record[j] = max(record[j]+1, grid[i][j]);
                result += (record[j] - grid[i][j]);
            }
        }
        return result;
    }
};

## [3403. Find the Lexicographically Largest String From the Box I](https://leetcode.com/problems/find-the-lexicographically-largest-string-from-the-box-i/) (<font color=#FFC011>Medium</font>)

### Solution

#### 時間複雜度:

#### 空間複雜度:

程式碼:

## [3404. Count Special Subsequences](https://leetcode.com/problems/count-special-subsequences/) (<font color=#FFC011>Medium</font>)

### Solution

#### 時間複雜度:

#### 空間複雜度:

程式碼:

## [3405. Count the Number of Arrays with K Matching Adjacent Elements](https://leetcode.com/problems/count-the-number-of-arrays-with-k-matching-adjacent-elements/) (<font color=#FF375F>Hard</font>)

### Solution

#### 時間複雜度:

#### 空間複雜度:

程式碼: