紫书动规 例题9-1 UVA

题目链接:

https://vjudge.net/problem/UVA-1025

题意:

题解:

代码:

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MS(a) memset(a,0,sizeof(a))
#define MP make_pair
#define PB push_back
const int INF = 0x3f3f3f3f;
const ll INFLL = 0x3f3f3f3f3f3f3f3fLL;
inline ll read(){
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
//////////////////////////////////////////////////////////////////////////
const int maxn = 12500+10;

int n,T;
int t[55],M1,d1[55],M2,d2[55];
int has_train[maxn][55][2];
int dp[maxn][55];

int main(){
    int cas = 1;
    while(cin >> n && n) {
        cin >> T;
        for(int i=1; i<n; i++)
            cin >> t[i];
        cin >> M1;
        for(int i=1; i<=M1; i++)
            cin >> d1[i];
        cin >> M2;
        for(int i=1; i<=M2; i++)
            cin >> d2[i];
        MS(has_train);
        for(int i=1; i<=M1; i++){
            int k = d1[i];
            for(int j=1; j<n; j++){
                has_train[k][j][0] = 1;
                k += t[j];
            }
            has_train[k][n][0] = 1;
        }
        for(int i=1; i<=M2; i++){
            int k = d2[i];
            has_train[k][n][1] = 1;
            for(int j=n-1; j>=1; j--){
                k += t[j];
                has_train[k][j][1] = 1;
            }
        }

        for(int j=0; j<=n; j++) dp[T][j] = INF;
        dp[T][n] = 0;

        for(int i=T-1; i>=0; i--){
            for(int j=n; j>=1; j--){
                dp[i][j] = dp[i+1][j] + 1;
                if(j<n && has_train[i][j][0] && i+t[j]<=T)
                    dp[i][j] = min(dp[i][j],dp[i+t[j]][j+1]);
                if(j>1 && has_train[i][j][1] && i+t[j-1]<=T)
                    dp[i][j] = min(dp[i][j],dp[i+t[j-1]][j-1]);
            }
        }

        if(dp[0][1] >= INF) printf("Case Number %d: impossible
",cas++);
        else printf("Case Number %d: %d
",cas++,dp[0][1]);
    }


    return 0;
}