Nowadays, a kind of chess game called “Super Jumping! Jumping! Jumping!” is very popular in HDU. Maybe you are a good boy, and know little about this game, so I introduce it to you now.
The game can be played by two or more than two players. It consists of a chessboard(棋盘)and some chessmen(棋子), and all chessmen are marked by a positive integer or “start” or “end”. The player starts from start-point and must jumps into end-point finally. In the course of jumping, the player will visit the chessmen in the path, but everyone must jumps from one chessman to another absolutely bigger (you can assume start-point is a minimum and end-point is a maximum.). And all players cannot go backwards. One jumping can go from a chessman to next, also can go across many chessmen, and even you can straightly get to end-point from start-point. Of course you get zero point in this situation. A player is a winner if and only if he can get a bigger score according to his jumping solution. Note that your score comes from the sum of value on the chessmen in you jumping path. Your task is to output the maximum value according to the given chessmen list. Input Input contains multiple test cases. Each test case is described in a line as follow: N value_1 value_2 …value_N It is guarantied that N is not more than 1000 and all value_i are in the range of 32-int. A test case starting with 0 terminates the input and this test case is not to be PRocessed. Output For each case, print the maximum according to rules, and one line one case. Sample Input 3 1 3 2 4 1 2 3 4 4 3 3 2 1 0 Sample Output 4 10 3
题意:求最大递增字段和。 一开始想着把每一个元素都做成一个单独的dp,还想过每个元素都作为一个阶段,其实没必要,自己还是做得太少了。这个的决策应该是,当前元素应该加到哪个序列里面,找以前的序列里面最大的。 状态转移方程 dp[i]=max(dp[i],dp[j]+v[i]);
#include <cstdio>#include <cstring>#include <string>#include <iostream>#include <algorithm>using namespace std;const int maxn=10010;int a[maxn];int dp[maxn];const int inf=0x7fffffff;int main(){ int n; while(cin>>n) { if(n==0) break; memset(a,0,sizeof(a)); for(int i=1;i<=n;i++) cin>>a[i]; memset(dp,0,sizeof(dp)); int ans; for(int i=1;i<=n;i++) { ans=-inf; for(int j=0;j<i;j++) { if(a[j]<a[i]) { ans=max(ans,dp[j]); } } dp[i]=ans+a[i]; } ans=-inf; for(int i=0;i<=n;i++) ans=max(ans,dp[i]); cout<<ans<<endl; }}新闻热点
疑难解答