Added more greedy techniques

algorithms/greedy/ClassPhoto.py

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+#Class Photo problem
+#Time O(nlongn) | Space O(1)
+
+def classPhotos(redShirtHeights, blueShirtHeights):
+
+    redShirtHeights.sort(reverse=True)
+	blueShirtHeights.sort(reverse=True)
+
+	shirtColorInFirstRow='RED' if redShirtHeights[0] < blueShirtHeights[0] else 'BLUE'
+	for i in range(len(redShirtHeights)):
+		redShirtHeight=redShirtHeights[i]
+		blueShirtHeight=blueShirtHeights[i]
+
+		if shirtColorInFirstRow=='RED':
+			if redShirtHeight>=blueShirtHeight:
+				return False
+		else:
+			if blueShirtHeight>=redShirtHeight:
+				return False
+	return True		
+

algorithms/greedy/MinimumWaitingTime.py

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+#Minimum Waiting Time
+#Time O(nLogn) for sorting array nlogn time takes and for keep tracking
+#it takes n time so total nlogn + n so simply negates nlogn since n is less than nlogn
+#So time O(N) and Space O(1) since we don't use extra space here
+
+def minimumWaitingTime(queries):
+    # Write your code here.
+    queries.sort()
+	totalWaitingTime=0
+	for idx,duration in enumerate(queries):
+		queriesLeft=len(queries)-(idx+1)
+		totalWaitingTime+=duration*queriesLeft
+	return totalWaitingTime