#3122

Minimum Number of Operations to Satisfy Conditions

Medium
ArrayDynamic ProgrammingMatrix
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Approaches

Brute ForceOptimal
Complexity Comparison
Brute ForceOptimal Solution
Time
O(n²)
O(n)
Space
O(1)
O(n)
💡

Intuition

Time O(n)Space O(n)

The optimal solution leverages the idea of grouping values in columns and ensuring that adjacent cells in rows are different. This reduces unnecessary operations by focusing on the relationships between cells rather than individual adjustments.

⚙️

Algorithm

3 steps
  1. 1Step 1: Create a frequency map for each column to count occurrences of each number.
  2. 2Step 2: For each column, determine the most frequent number and calculate the number of operations needed to make all cells in that column equal to this number.
  3. 3Step 3: For each row, ensure that adjacent cells are different by adjusting values based on the previous column's most frequent number.
solution.py12 lines
1# Full working Python code
2
3def min_operations(grid):
4    from collections import Counter
5    m, n = len(grid), len(grid[0])
6    operations = 0
7    for j in range(n):
8        count = Counter(grid[i][j] for i in range(m))
9        most_common = count.most_common(1)[0][1]
10        operations += m - most_common
11    return operations
12

Complexity note: The time complexity is O(n) because we only need to iterate through each column once to count occurrences. The space complexity is O(n) due to the frequency map used to store counts of each number in the columns.

  • 1Focus on column relationships to minimize operations.
  • 2Utilize frequency counts to determine optimal adjustments.

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