tags: Weekly Contest

Weekly Contest 430

3402. Minimum Operations to Make Columns Strictly Increasing (Easy)

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 (Medium)

Solution

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程式碼:

3404. Count Special Subsequences (Medium)

Solution

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程式碼:

3405. Count the Number of Arrays with K Matching Adjacent Elements (Hard)

Solution

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程式碼: