BZOJ 1649: [Usaco2006 Dec]Cow Roller Coaster( dp )

有点类似背包 , 就是那样子搞...

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#include<cstdio>

#include<cstring>

#include<algorithm>

#include<iostream>

#define rep( i , n ) for( int i = 0 ;  i < n ; ++i )

#define clr( x , c ) memset( x , c , sizeof( x ) )

#define Rep( i , n ) for( int i = 1 ; i <= n ; ++i )

 

using namespace std;

 

const int maxn = int( 1e4 ) + 5;

const int maxl = 1000 + 5;

const int maxc = 1000 + 5;

const int inf = 0x7fffffff;

 

struct data {

int x , l , w , c;

void Read() {

scanf( "%d%d%d%d" , &x , &l , &w , &c );

}

bool operator < ( const data &rhs ) const {

return x < rhs.x || ( x == rhs.x && l < rhs.l );

}

};

 

data A[ maxn ];

int d[ maxl ][ maxc ];

 

int main() {

// freopen( "test.in" , "r" , stdin );

int L , n , MAX;

scanf( "%d%d%d" , &L , &n , &MAX );

MAX++;

rep( i , n ) 

   A[ i ].Read();

   

Rep( i , L )

   rep( j , MAX )

       d[ i ][ j ] = -inf;

rep( i , MAX )

   d[ 0 ][ i ] = 0;

sort( A , A + n );

rep( i , n ) {

data &o = A[ i ];

for( int j = o.c ; j < MAX ; j++ ) {

int &f = d[ o.x + o.l ][ j ];

f = max( f , d[ o.x ][ j - o.c ] + o.w );

}

}

int ans = 0;

rep( i , MAX ) ans = max( ans , d[ L ][ i ] );

ans > 0 ? printf( "%d\n" , ans ) : printf( "-1\n" );

return 0;

}

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1649: [Usaco2006 Dec]Cow Roller Coaster

Time Limit: 5 Sec  Memory Limit: 64 MB
Submit: 440  Solved: 233
[Submit][Status][Discuss]

Description

The cows are building a roller coaster! They want your help to design as fun a roller coaster as possible, while keeping to the budget. The roller coaster will be built on a long linear stretch of land of length L (1 <= L <= 1,000). The roller coaster comprises a collection of some of the N (1 <= N <= 10,000) different interchangable components. Each component i has a fixed length Wi (1 <= Wi <= L). Due to varying terrain, each component i can be only built starting at location Xi (0 <= Xi <= L-Wi). The cows want to string together various roller coaster components starting at 0 and ending at L so that the end of each component (except the last) is the start of the next component. Each component i has a "fun rating" Fi (1 <= Fi <= 1,000,000) and a cost Ci (1 <= Ci <= 1000). The total fun of the roller coster is the sum of the fun from each component used; the total cost is likewise the sum of the costs of each component used. The cows' total budget is B (1 <= B <= 1000). Help the cows determine the most fun roller coaster that they can build with their budget.

奶牛们正打算造一条过山车轨道．她们希望你帮忙，找出最有趣，但又符合预算的方案．  过山车的轨道由若干钢轨首尾相连，由x=0处一直延伸到X=L(1≤L≤1000)处．现有N(1≤N≤10000)根钢轨，每根钢轨的起点Xi(0≤Xi≤L- Wi)，长度wi(l≤Wi≤L)，有趣指数Fi(1≤Fi≤1000000)，成本Ci(l≤Ci≤1000)均己知．请确定一种最优方案，使得选用的钢轨的有趣指数之和最大，同时成本之和不超过B(1≤B≤1000)．

Input

* Line 1: Three space-separated integers: L, N and B.

* Lines 2..N+1: Line i+1 contains four space-separated integers, respectively: Xi, Wi, Fi, and Ci.

    第1行输入L，N，B，接下来N行，每行四个整数Xi，wi，Fi，Ci．

Output

* Line 1: A single integer that is the maximum fun value that a roller-coaster can have while staying within the budget and meeting all the other constraints. If it is not possible to build a roller-coaster within budget, output -1.

Sample Input

5 6 10
0 2 20 6
2 3 5 6
0 1 2 1
1 1 1 3
1 2 5 4
3 2 10 2

Sample Output

17
选用第3条，第5条和第6条钢轨

HINT

Source

Silver