Reshape Matrix

reshape-matrix.java

class Solution {
  public int[][] reshapeMatrix(int[][] matrix, int r, int c) {
      
    int rows = matrix.length;
    int cols = matrix[0].length;
    if ((rows * cols) != (r * c)) throw new RuntimeException("Invalid operation");
    
    int[][] resultMatrix = new int[r][c];
    int  resultRow = 0;
    int resultCol = 0;
    // traverse original matrix and fill in the result matrix 
    for(int i = 0; i < rows; i++) {
      for (int j = 0; j < cols; j++) {
        resultMatrix[resultRow][resultCol] = matrix[i][j];
        if (resultCol == c - 1) {
          resultCol = 0;
          resultRow += 1;
        } else {
          resultCol += 1;
        }
      }
    }
    return resultMatrix;
  }
}