Cod sursa(job #637376)

Utilizator PlayLikeNeverB4George Marcus PlayLikeNeverB4 Data 20 noiembrie 2011 14:09:44
Problema PalM Scor 90
Compilator cpp Status done
Runda .com 2011 Marime 0.99 kb
#include <cstdio>
#include <string.h>
#include <algorithm>
#include <stdlib.h>
using namespace std;

#define MAXN 512
char S[MAXN];
int i,len,j,p,q,N,L,Lmax;
int mem[MAXN][MAXN],P[MAXN][MAXN],Ind[MAXN][MAXN];

int caut(int a, int b) {
	if(a>b) return 0;
	if(a==b && S[a]>=S[a-1]) return 1;
	if(mem[a][b]>=0) return mem[a][b];
	
	int i,j,R=0;
	for(i=a;i<b;i++) {
		if(S[i]<S[a-1]) continue;
		R=max(R,1);
		j=Ind[i][b];
		if(j==0 || j<i) continue;
		R=max(R,2+caut(i+1,j-1));
	}
	return mem[a][b]=R;
}


int main() {
	freopen("palm.in","r",stdin);
	freopen("palm.out","w",stdout);
	
	fgets(S,sizeof(S),stdin);
	N=strlen(S);
	while(S[N-1]<'a' || S[N-1]>'z') N--;
	
	for(i=0;i<N-1;i++)
		for(j=i+1;j<N;j++) {
			if(S[i]==S[j])
				P[i][++P[i][0]]=j;
			Ind[i][j]=P[i][P[i][0]];    // <=j
		}
	
	for(i=0;i<N;i++)
		for(j=i;j<N;j++)
			mem[i][j]=-1;
	
	Lmax=1;
	for(i=0;i<N-1;i++) {
		q=P[i][0];
		if(q==0) continue;
		j=P[i][q];
		if(j<=i) continue;
		L=2+caut(i+1,j-1);
		Lmax=max(Lmax,L);
	}
	
	printf("%d",Lmax);
}