codeforce E. Fire背包
2 seconds
256 megabytes
standard input
standard output
Polycarp is in really serious trouble — his house is on fire! It's time to save the most valuable items. Polycarp estimated that it would take ti seconds to save i-th item. In addition, for each item, he estimated the value of di — the moment after which the item i will be completely burned and will no longer be valuable for him at all. In particular, if ti ≥ di, then i-th item cannot be saved.
Given the values pi for each of the items, find a set of items that Polycarp can save such that the total value of this items is maximum possible. Polycarp saves the items one after another. For example, if he takes item a first, and then item b, then the item a will be saved in ta seconds, and the item b — in ta + tb seconds after fire started.
The first line contains a single integer n (1 ≤ n ≤ 100) — the number of items in Polycarp's house.
Each of the following n lines contains three integers ti, di, pi (1 ≤ ti ≤ 20, 1 ≤ di ≤ 2 000, 1 ≤ pi ≤ 20) — the time needed to save the item i, the time after which the item i will burn completely and the value of item i.
In the first line print the maximum possible total value of the set of saved items. In the second line print one integer m — the number of items in the desired set. In the third line print m distinct integers — numbers of the saved items in the order Polycarp saves them. Items are 1-indexed in the same order in which they appear in the input. If there are several answers, print any of them.
3
3 7 4
2 6 5
3 7 6
11
2
2 3
2
5 6 1
3 3 5
1
1
1
In the first example Polycarp will have time to save any two items, but in order to maximize the total value of the saved items, he must save the second and the third item. For example, he can firstly save the third item in 3 seconds, and then save the second item in another 2 seconds. Thus, the total value of the saved items will be 6 + 5 = 11.
In the second example Polycarp can save only the first item, since even if he immediately starts saving the second item, he can save it in 3 seconds, but this item will already be completely burned by this time.
典型背包题
但是要排序先,因为如果有一个任务的deadline是8,时间是5,,然后价值是100861,另一个任务的deadline是2,时间是1,价值是1,那么第二个任务不会被计入,就产生了错误
就是不具有那种一般背包的元素随便放的条件这个是有一个限制条件在deadline前,那么从小到大用deadline排序就可以变成基本的一维背包了
#include<cstdio>
#include<vector>
#include<cstring>
#include<algorithm>
using namespace std;
const int N=;
struct node
{
int ed,ne,val,id;
bool operator < (const node &A)const{
return ed<A.ed;
}
} e[N];
struct ct
{
int val;
vector<int>s;
ct()
{
val=;
s.clear();
}
} dp[N<<];
int main()
{
int maxx=,n;
scanf("%d",&n);
for(int i=; i<=n; ++i)
{
scanf("%d%d%d",&e[i].ne,&e[i].ed,&e[i].val);
maxx=max(maxx,e[i].ed);
e[i].id=i;
}
sort(e+,e+n+);
for(int i=; i<=n; ++i)
{
if(e[i].ed<=e[i].ne) continue;
for(int j=e[i].ed; j>=; --j)
{
if(j-e[i].ne<=) break;
if(dp[j].val<dp[j-e[i].ne].val+e[i].val)
{
dp[j].val=dp[j-e[i].ne].val+e[i].val;
dp[j].s.clear();
for(int k=; k<(int)dp[j-e[i].ne].s.size(); ++k) dp[j].s.push_back(dp[j-e[i].ne].s[k]);
dp[j].s.push_back(e[i].id);
}
}
}
int k=maxx;
for(int i=;i<=maxx;++i) if(dp[i].val>dp[k].val) k=i;
printf("%d\n%d\n",dp[k].val,dp[k].s.size());
for(int i=; i<(int)dp[k].s.size(); ++i) printf("%d ",dp[k].s[i]);
puts("");
}
这个是别人的干净清爽的代码。。
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int N = ;
const int M = ;
int n;
int dp[M], vis[N][M];
struct node {
int t, d, p, id;
bool operator < (const node&r) const{
return d < r.d;
}
}a[N];
int b[N];
int main() {
int i, j, k, t, ed = , cnt = ;
memset(dp, , sizeof(dp)); memset(vis, , sizeof(vis));
scanf("%d", &n);
for(i = ; i <= n; ++i) {
scanf("%d%d%d", &a[i].t, &a[i].d, &a[i].p);
a[i].id = i;
}
sort(a+, a++n);
for(i = ; i <= n; ++i) {
t = a[i].t;
for(j = a[i].d-; j >= t; --j) {
if(dp[j] < dp[j-t]+a[i].p) {
dp[j] = dp[j-t] + a[i].p;
vis[i][j] = ;
}
}
}
for(i = ; i < a[n].d; ++i) if(dp[i]>dp[ed]) ed = i;
printf("%d\n", dp[ed]);
for(i = n; i >= ; --i) {
if(vis[i][ed]) {b[cnt++] = a[i].id; ed -= a[i].t;}
}
printf("%d\n", cnt);
for(i = cnt-; i > ; --i) printf("%d ", b[i]);
if(cnt) printf("%d\n", b[]);
return ;
}
codeforce E. Fire背包的更多相关文章
- Codeforce E. Fire
E. Fire time limit per test 2 seconds memory limit per test 256 megabytes input standard input outpu ...
- codeforce 35C fire again
2017-08-25 17:04:07 writer:pprp 题目描述: • Codeforces 35C Fire Again• N*M的格子,最开始有K个点 (坐标给定) 开始着火• 每一秒着火 ...
- codeforces 864 E. Fire(背包+思维)
题目链接:http://codeforces.com/contest/864/problem/E 题解:这题一看就很像背包但是这有3维限制也就是说背包取得先后也会对结果有影响.所以可以考虑sort来降 ...
- UVALive 5066 Fire Drill BFS+背包
H - Fire Drill Time Limit:3000MS Memory Limit:0KB 64bit IO Format:%lld & %llu Submit Sta ...
- Coderfroces 864 E. Fire(01背包+路径标记)
E. Fire http://codeforces.com/problemset/problem/864/E Polycarp is in really serious trouble — his h ...
- codeforce Gym 101102A Coins (01背包变形)
01背包变形,注意dp过程的时候就需要取膜,否则会出错. 代码如下: #include<iostream> #include<cstdio> #include<cstri ...
- Codeforces Round #436 E. Fire(背包dp+输出路径)
题意:失火了,有n个物品,每个物品有价值pi,必须在时间di前(小于di)被救,否则就要被烧毁.救某个物 品需要时间ti,问最多救回多少价值的物品,并输出救物品的顺序. Examples Input ...
- Codeforces 864E Fire(背包DP)
背包DP,决策的时候记一下 jc[i][j]=1 表示第i个物品容量为j的时候要选,输出方案的时候倒推就好了 #include<iostream> #include<cstdlib& ...
- Codeforces Round #436 (Div. 2) E. Fire(背包+记录路径)
传送门 题意 给出n种物品,抢救第\(i\)种物品花费时间\(t_i\),价值\(p_i\),截止时间\(d_i\) 询问抢救的顺序及物品价值和最大值 分析 按\(d_i\)排序的目的是防止以下情况 ...
随机推荐
- 【阅读笔记】Ranking Relevance in Yahoo Search (三)—— query rewriting
5. QUERY REWRITING 作用: query rewriting is the task of altering a given query so that it will get bet ...
- CF思维联系--CodeForces -214C (拓扑排序+思维+贪心)
ACM思维题训练集合 Furik and Rubik love playing computer games. Furik has recently found a new game that gre ...
- The Preliminary Contest for ICPC Asia Xuzhou 2019 徐州网络赛 K题 center
You are given a point set with nn points on the 2D-plane, your task is to find the smallest number o ...
- css实现水平垂直居中的几种方式
梳理下平时常用css水平垂直居中方式- 使用flex布局 HTML <div class="box"> <div class="child"& ...
- RocketMQ-架构篇
RocketMQ-架构篇 1.Broker Broker是RocketMQ的服务端组件之一,所有消息存储在Broker上,所有的投递.消费请求也都由Broker进行处理.Broker是有状态的应用,本 ...
- Ubuntu开机黑屏解决办法
联想笔记本通过虚拟机安装Ubuntu12.04后,开机黑屏.这个问题和NVIDIA显卡有关.网上有人提到更改/etc/default/grub文件,可是我通过root身份也无法很好地修改该文件,遂放弃 ...
- Halloween Costumes 玄学题
传送门 太难了,完全不懂 设\(dp[i][j]\)为第i天到第j天的最少代价 \(dp[i][j]=dp[i][j-1]+1\)(第j天多穿一件衣服) \(dp[i][j]=min(dp[i][j] ...
- Struts Scan工具的使用
前言 最近看了关于Struts2漏洞,参考文章 https://www.freebuf.com/vuls/168609.html,这篇文章里对Struts2的漏洞及原理进行了详细的讲解.自己也从网上找 ...
- CC2530ADC应用
ADC单通道外部电压采集 需要设置一个上机位命令控制字符. 系统时钟初始化——32MHZ晶振 串口0函数初始化——设置串口对应引脚,波特率,清楚中断标志 串口0接收中断响应函数——U0DBUF将控制命 ...
- 面试官:你说你懂动态代理,那你知道为什么JDK中的代理类都要继承Proxy吗?
之前我已经写过了关于动态代理的两篇文章,本来以为这块应该没啥问题,没想到今天又被难住了- 太难了!!! 之前文章的链接: 动态代理学习(一)自己动手模拟JDK动态代理. 动态代理学习(二)JDK动态代 ...