Added ROCK from SPOJ

Author: Sethi

ROCK/problem.txt

@@ -0,0 +1,3 @@
+https://www.spoj.com/problems/ROCK/
+
+#dynamicprogramming

ROCK/rock.cpp

@@ -0,0 +1,113 @@
+/*
+***************************************************************************************************************
+ 
+                          Author : SUBHENDU SETHI
+                          Hackerrank Handle: subhendu_sethi
+                          Codechef Handle: subhendu_sethi
+                          SPOJ Handle: codekatte
+                          Codeforces Handle: subhendu_sethi
+                          UVA Handle: codekatte
+ 
+**************************************************************************************************************
+*/
+#include <bits/stdc++.h>
+using namespace std;
+ 
+#define ll long long
+#define si(x) scanf("%d",&x)
+#define sl(x) scanf("%lld",&x)
+#define slu(x) scanf("%llu",&x)
+#define sd(x) scanf("%lf",&x)
+#define sc(x) scanf("%c",&x)
+#define ss(x) scanf("%s",x)
+#define vl vector<ll>
+#define vi vector<int>
+#define pb push_back
+#define MOD 1000000007
+#define MAXN 105050
+#define SQRT 330
+#define ls (node<<1)
+#define rs ((node<<1)+1)
+#define ii pair<int,int>
+#define F first
+#define S second
+#define f(i,a,b) for(int i=a;i<b;i++)
+ll dp[250][250];
+char S[250];
+ll n,t;
+ll num0[250];
+ll num1[250];
+inline void refresh()
+{
+	memset(dp,-1,sizeof(dp));
+	memset(num0,0,sizeof(num0));
+	memset(num1,0,sizeof(num1));
+}
+inline void read()
+{ 
+	sl(t);
+} 
+ll rec(int a, int b)
+{
+	if(dp[a][b] != -1){
+		return dp[a][b];
+	}
+	else if(a>b){
+		return dp[a][b] = 0;
+	}
+	else if(a == b)
+	{
+		if(S[a] == '0')
+			return dp[a][b] = 0;
+		return dp[a][b] = 1;
+	}
+	else
+	{
+		ll tot0 = num0[b];
+		ll tot1 = num1[b];
+		if(a!=0){
+			tot0-=num0[a-1];
+			tot1-=num1[a-1];
+		}
+		if(tot1>tot0)
+			return dp[a][b] = (b-a+1);
+		else
+		{
+			ll ret = 0;
+			for(int i=a;i<b;i++)
+			{
+				ret = max(ret,rec(a,i)+rec(i+1,b));
+			}
+			return dp[a][b] = ret;
+		}
+	}
+}
+inline void solve()
+{ 
+	while(t--)
+	{
+		refresh();
+		sl(n);
+		scanf("%s",S);
+		f(i,0,n)
+		{
+			if(S[i] == '0')
+				num0[i]=1;
+			else
+				num1[i]=1;
+		}
+		f(i,1,n)
+		{
+			num0[i]+=num0[i-1];
+			num1[i]+=num1[i-1];
+		}
+		ll ans = rec(0,n-1);
+		printf("%lld\n",ans);
+	}
+}  
+int main() 
+{
+    read();
+    solve();
+    return 0;
+}