CSP模拟赛#3 分段(T1-26)

题目地址

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#include<cstdio>
#include<iostream>
#include<cstring>
#define int long long
using namespace std;
const int MAXN=4e3,INF=2e9;
char str[MAXN];
int w[MAXN];
int a[MAXN][MAXN];//l r
int n;
int getValue(int l,int r){
	if(l>r)return 0;
	if((r-l+1)%2!=0)return INF;
	int rest=0;
	if(str[l-1]!=str[r-1])rest=min(w[l],w[r]);
	return getValue(l+1,r-1)+rest;
}
void init(){
	memset(a,0,sizeof(a));
	for(int l=1;l<=n;l++){
		for(int r=l+1;r<=n;r++){
			if((l%2)==0)continue;
			a[l][r]=getValue(l,r);
			//printf("a[%lld][%lld]=%lld\n",l,r,a[l][r]);
		}
	}
}
int f[MAXN];
void test(){
	init();
	memset(f,0x3f,sizeof(f));
	f[2]=a[1][2];
	f[0]=0;
	for(int i=2;i<=n;i+=2){
		for(int j=0;j<=i-2;j+=2){
			f[i]=min(f[i],f[j]+a[j+1][i]);
			//printf("f[%d]=%d\n",i,f[i]);
		}
	}
	cout<<f[n]<<endl;
}
signed main(){
	scanf("%lld",&n);
	cin>>str;
	for(int i=1;i<=n;i++){
		cin>>w[i];
	}
	test();
	return 0;
}