Leader.c

Author: ssdash

DataStructure/Array/Leader.c

@@ -0,0 +1,51 @@
+/** Program: A Leader in an array
+ *  For a Leader 'L' all elements on right side of 'L' are lessthen
+ *  'L'
+ *  Input: arr[] = {15,16,3,2,6,1,4}
+ *  Output:16,6,4 
+ *  (Last array element is always a leader since there is no element
+ *  right to last element)
+ */  
+#include<stdio.h>
+/* Time complexcity O(n^2) */
+void findLeader(int arr[],int n)
+{
+    int i,j;
+    for(int i=0;i<n;i++)
+    {
+	for(j=i+1;j<n;j++)
+	{
+	    if(arr[j] >= arr[i])
+		break;
+	}
+        if(j == n)
+	printf("%d is Leader\n",arr[i]);
+    }
+}
+
+/** Efficient method for finding Leader 
+ *  Time complexcity O(n)
+ */
+void findLeader1(int arr[],int n)
+{
+    int end = arr[n-1];
+    for(int i=n;i>=0;i--)
+    {
+	if(arr[i]>=end)
+	{
+	    end = arr[i];
+	    printf("%d is Leader",end);
+	    printf("\n");
+	 }
+    }
+ }
+
+int main()
+{
+    int arr[] = {15,16,3,2,6,1,4};
+    int n = sizeof(arr)/sizeof(arr[0]);
+    findLeader(arr,n);
+    findLeader1(arr,n);
+
+    return 0;
+}