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public class NumberOfIncreasingPaths {
private static final int MOD = 1_000_000_007;
public static int countIncreasingPaths(int[][] matrix) {
int m = matrix.length;
int n = matrix[0].length;
int[][] memo = new int[m][n]; // Memoization array to store results
int totalPaths = 0;
// Iterate over all cells to count all increasing paths
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
totalPaths = (totalPaths + dfs(matrix, i, j, memo)) % MOD;
}
}
return totalPaths;
}
private static int dfs(int[][] matrix, int row, int col, int[][] memo) {
// If already computed, return the memoized result
if (memo[row][col] != 0) {
return memo[row][col];
}
int m = matrix.length;
int n = matrix[0].length;
int pathCount = 1; // Count the path starting from the current cell
// Directions: up, down, left, right
int[][] directions = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};
for (int[] dir : directions) {
int newRow = row + dir[0];
int newCol = col + dir[1];
// Move to the new cell if it's within bounds and greater than the current cell
if (newRow >= 0 && newRow < m && newCol >= 0 && newCol < n && matrix[newRow][newCol] > matrix[row][col]) {
pathCount = (pathCount + dfs(matrix, newRow, newCol, memo)) % MOD;
}
}
// Store the result in the memoization array
memo[row][col] = pathCount;
return pathCount;
}
public static void main(String[] args) {
int[][] matrix1 = {{1, 2}, {3, 4}};
System.out.println(countIncreasingPaths(matrix1)); // Output: 10
int[][] matrix2 = {{9, 9, 4}, {6, 6, 8}, {2, 1, 1}};
System.out.println(countIncreasingPaths(matrix2)); // Output: 21
int[][] matrix3 = {{3, 4, 5}, {3, 2, 6}, {2, 2, 1}};
System.out.println(countIncreasingPaths(matrix3)); // Output: 21
}
}
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