day 5, max of row which is min of col

day5_row_min_col_max.py

@@ -0,0 +1,29 @@
+# Required concepts: https://www.w3schools.com/python/python_intro.asp lists and functions
+
+print('Question: Element which is min in its row and max in column')
+matrix = [[1,2,3],
+          [4,5,6],
+          [7,8,9]]
+
+def rowMinColMax(matrix):
+  rowMin,colMax = [],[]
+  for row in matrix:
+    # find and store max of each row
+    rowMin.append(min(row))
+  for i in range(len(matrix[0])):
+    # find and store max of each col
+    maxi = matrix[0][i]
+    # just travel the col from up to down, and update maxi
+    for j in range(len(matrix)):
+      maxi = max(maxi,matrix[j][i])
+    colMax.append(maxi)
+
+  #now find the overlap
+  for i in range(len(matrix)):
+    for j in range(len(matrix[0])):
+      if rowMin[i] == colMax[j] == matrix[i][j]:
+        return matrix[i][j]
+  return False
+
+print('Answer:')
+print(rowMinColMax(matrix))

main.py

@@ -1,18 +1,29 @@
-# Required concepts: https://www.w3schools.com/python/python_intro.asp lists
-
-print('Question: Maximum product of two elements in array')
-
-
-
-li = [-7,-6,4,1,2,3,4,5,6]
-li.sort()
-# 5*6 or -7*-6 only those could give me the maximum
-# product of the two smallest, neg*neg 
-first = li[0]*li[1]
-last = li[-1]*li[-2]
+# Required concepts: https://www.w3schools.com/python/python_intro.asp lists and functions
+
+print('Question: Element which is min in row and max in column')
+matrix = [[1,2,3],
+          [4,5,6],
+          [7,8,9]]
+
+def rowMinColMax(matrix):
+  rowMin,colMax = [],[]
+  for row in matrix:
+    rowMin.append(min(row))
+  for i in range(len(matrix[0])):
+    maxi = matrix[0][i]
+    for j in range(len(matrix)):
+      maxi = max(maxi,matrix[j][i])
+    colMax.append(maxi)
+
+  #now find the overlap
+  for i in range(len(matrix)):
+    for j in range(len(matrix[0])):
+      if rowMin[i] == colMax[j] == matrix[i][j]:
+        return matrix[i][j]
+  return False
 
 print('Answer:')
-print(max(first,last))
+print(rowMinColMax(matrix))