Added Longest Increasing Subsequence

Data Structure & Algorithm/longest-Increasing-Subsequence.c

@@ -0,0 +1,84 @@
+/*
+This code has been written by Manas Ranjan Swain (https://github.com/Manas173/)
+
+Description: Given an array of N elements print the size of the longest icreasing subsequence present in the array.
+
+Input:
+The first line contains an integer T, depicting total number of test cases. Then following T lines contains an integer N depicting the size of array and next line followed by the value of array.
+
+Output:
+For each testcase, in a new line, print the Max length of the subsequence in a separate line.
+
+
+Sample testcase:
+
+INPUT:
+2
+8
+10 9 2 5 3 7 101 18
+6
+5 8 3 7 9 1
+
+OUTPUT:
+4
+3
+
+EXPLANATION:
+For the first testcase, 2,3,7,101 
+For the second testcase, 5,7,9 and 3,7,9 are the possibilities
+*/
+
+#include <stdio.h>
+
+int lis(int *arr,int *mem,int pos,int size)
+{
+    int max=1;
+    if(mem[pos]!=-1)
+        return mem[pos];
+
+    for(int i=pos+1;i<size;i++)
+    {
+        if(arr[pos]<arr[i])
+        {
+            int temp=lis(arr,mem,i,size)+1;
+            if(temp>max)
+                max=temp;
+        }
+    }
+    mem[pos]=max;
+    return mem[pos];
+}
+
+int main()
+{
+    int t;
+    scanf("%d",&t);
+    while(t--)
+    {
+        int size;
+        scanf("%d",&size);
+        int arr[size];
+        int mem[size];
+
+        for(int i=0;i<size;i++)
+        {
+            scanf("%d",&arr[i]);
+            mem[i]=-1;
+        }
+
+        if(size>0)
+        {
+            mem[size-1]=1;
+            int ans=0;
+            for(int i=size-1;i>=0;i--)
+            {
+                mem[i]=lis(arr,mem,i,size);
+                if(ans<mem[i])
+                    ans=mem[i];
+            }
+            printf("%d\n",ans);
+        }
+        else
+            printf("0");
+    }
+}