Akhmad228's blog

Interesting problem
By Akhmad228, history, 8 years ago, In English

I have interesting problem from WCIP3G. I thought that is DP.

And in my DP I have 2 states.

dp[i][j] = answer for subsequence from i to j.

Transitions obviously will be dp[i + 1][j] and dp[i][j - 1].

But how it can be written?

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8 years ago, hide # |
 
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#define rg register
#define MAXN 110

int n;
int dp[MAXN];
int sum[MAXN];

int main(){
	ms(sum);

	read(n);
	for( rg int i = 1 ; i <= n ; i++ ){
		read(dp[i]);
		sum[i] = sum[i-1] + dp[i];
	}

	for( rg int i = n-1 ; i >= 1 ; i-- )
		for( rg int j = i+1 ; j <= n ; j++ ){
			rg int dp1 = sum[j] - sum[i-1] - dp[j];
			rg int dp2 = sum[j] - sum[i-1] - dp[j-1];
			dp[j] = max( dp1 , dp2 );
		}

	printf("%d\n",dp[n] );

	return 0;
}
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