Added #195

Author: subsr97

challenges/count-elements-given-upper-and-lower-bounds.py

@@ -0,0 +1,82 @@
+"""
+#195
+Google
+
+Let A be an N by M matrix in which every row and every column is sorted.
+
+Given i1, j1, i2, and j2, compute the number of elements of M smaller than M[i1, j1] and larger than M[i2, j2].
+
+For example, given the following matrix:
+
+[[1, 3, 7, 10, 15, 20],
+ [2, 6, 9, 14, 22, 25],
+ [3, 8, 10, 15, 25, 30],
+ [10, 11, 12, 23, 30, 35],
+ [20, 25, 30, 35, 40, 45]]
+
+And i1 = 1, j1 = 1, i2 = 3, j2 = 3, return 15 as there are 15 numbers in the matrix smaller than 6 or greater than 23.
+
+"""
+
+# Uncomment all print statements to see the valid upper and lower bound elements and their respective count
+def countElements(matrix, upperBound, lowerBound):
+    N = len(matrix)
+    M = len(matrix[0])
+
+    upperBoundCount = 0
+    lowerBoundCount = 0
+
+    # print("Upper bound elements: ", end = " ")
+    for i in range(N):
+        if matrix[i][0] >= upperBound:
+            break
+        else:
+            # print(matrix[i][0], end = " ")
+            upperBoundCount += 1
+        
+        for j in range(1, M):
+            if matrix[i][j] >= upperBound:
+                break
+            # print(matrix[i][j], end = " ")
+            upperBoundCount += 1
+
+    # print("\nLower Bound Elements: ", end = " ")
+    for i in range(N-1, -1, -1):
+        if matrix[i][M-1] <= lowerBound:
+            break
+        else:
+            # print(matrix[i][M-1], end = " ")
+            lowerBoundCount += 1
+        
+        for j in range(M-2, -1, -1):
+            if matrix[i][j] <= lowerBound:
+                break
+            # print(matrix[i][j], end = " ")
+            lowerBoundCount += 1
+
+    # print("\nUpper Bound Count:", upperBoundCount, "\nLower Bound Count:", lowerBoundCount)
+    return upperBoundCount + lowerBoundCount
+        
+
+def main():
+    matrix = [
+        [1, 3, 7, 10, 15, 20],
+        [2, 6, 9, 14, 22, 25],
+        [3, 8, 10, 15, 25, 30],
+        [10, 11, 12, 23, 30, 35],
+        [20, 25, 30, 35, 40, 45]
+    ]
+
+    i1 = 1
+    j1 = 1
+
+    i2 = 3
+    j2 = 3
+
+    upperBound = matrix[i1][j1]
+    lowerBound = matrix[i2][j2]
+
+    print(countElements(matrix, upperBound, lowerBound))
+
+if __name__ == "__main__":
+    main()