hdu5009Paint Pearls dp

来源：互联网发布：数据库王珊第5版答案编辑：程序博客网时间：2024/06/07 06:08
#include<cstdio>#include<cstring>#include<iostream>#include<map>#include<algorithm>using namespace std ;const int maxn = 5e4+10 ;const int inf = 1e9 ;int dp[maxn] ;int a[maxn] ;map<int,int> ma;int pre[maxn] ;int last[maxn] ;int main(){    int n ;    while(~scanf("%d" , &n))    {        int len = 0 ;        ma.clear() ;        for(int i = 1;i <= n;i++){           scanf("%d" , &a[i]) ;           if(ma[a[i]] == 0){              ma[a[i]] = ++len ;           }        }        for(int i = 1;i <= n;i++){            a[i] = ma[a[i]]  ;            dp[i] = inf ;        }        dp[0] = 0 ;        memset(pre , -1 , sizeof(pre)) ;        memset(last , 0 , sizeof(last)) ;        for(int i = n;i > 0;i--){            if(last[a[i]])               pre[last[a[i]]] = i ;            last[a[i]] = i ;        }        dp[n] = n ;dp[0] = 0 ;        for(int i = 0;i <= n;i++){            int cnt = 0 ;            for(int j = i+1;j <= n;j++){                if(pre[j] <= i){                   cnt++ ;                }                int tmp = cnt*cnt ;                if(tmp + dp[i] > dp[n])                break ;                dp[j] = min(dp[j] , dp[i]+tmp) ;            }        }        printf("%d\n" , dp[n]) ;    }    return  0 ;}
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