心急的C小加(两种解法)

心急的C小加

时间限制:1000 ms  |  内存限制:65535 KB
难度:4
 
描述

C小加有一些木棒,它们的长度和质量都已经知道,需要一个机器处理这些木棒,机器开启的时候需要耗费一个单位的时间,如果第i+1个木棒的重量和长度都大 于等于第i个处理的木棒,那么将不会耗费时间,否则需要消耗一个单位的时间。因为急着去约会,C小加想在最短的时间内把木棒处理完,你能告诉他应该怎样做 吗?

输入
第一行是一个整数T(1<T<1500),表示输入数据一共有T组。
每组测试数据的第一行是一个整数N(1<=N<=5000),表示有N个木棒。接下来的一行分别输入N个木棒的L,W(0 < L ,W <= 10000),用一个空格隔开,分别表示木棒的长度和质量。
输出
处理这些木棒的最短时间。
样例输入
3
5
4 9 5 2 2 1 3 5 1 4
3
2 2 1 1 2 2
3
1 3 2 2 3 1
样例输出
2
1
3 先贴下自己的dp超时代码:
 #include<stdio.h>
#include<algorithm>
#define MAX(x,y) x>y?x:y
using namespace std;
struct Case{
int L,W;
}strick[];
int cmp(Case a,Case b){
if(a.L==b.L)return a.W<b.W;
else return a.L<b.L;
}
int main(){
int T,N,dp[],max;
scanf("%d",&T);
while(T--){
scanf("%d",&N);
for(int i=;i<N;++i){dp[i]=;
scanf("%d%d",&strick[i].L,&strick[i].W);
}
sort(strick,strick+N,cmp);
max=;
for(int i=;i<N;++i){
for(int j=;j<=i;++j){
if(strick[j].W>strick[i].W)dp[i]=dp[j]+;
max=MAX(dp[i],max);
}
}
printf("%d\n",max);
}
return ;
}
借助大神理解解写的代码:
 #include<stdio.h>

 #include<algorithm>

 using namespace std;

 struct Case{

     int L,W,dis;

 };

 struct Case stick[];

 int cmp(Case a,Case b){

     if(a.L==b.L)return a.W<b.W;

     else return a.L<b.L;

 }

 int main(){int T,N,t,flot;

 scanf("%d",&T);

 while(T--){

     scanf("%d",&N);

     for(int i=;i<N;++i)scanf("%d%d",&stick[i].L,&stick[i].W),stick[i].dis=;

     sort(stick,stick+N,cmp);flot=;

     for(int i=;i<N;++i){

         if(stick[i].dis==)continue;

         t=stick[i].W;

         for(int j=i+;j<N;++j){

             if(stick[j].dis&&t<=stick[j].W)stick[j].dis=,t=stick[j].W;

         }

         flot++;

     }

     printf("%d\n",flot);

 }

     return ;

 }

/*题解:


结构体排序,一级排木棒的重量,二级排木棒的长度,均由小到大。


进行了多少次外层循环,就是花费的分钟数。


*/ 

若排序后,如图:

心急的C小加(两种解法)

则,花费了2分钟。 

Wooden Sticks

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 14880    Accepted Submission(s): 6105
Problem Description
There is a pile of n wooden sticks. The length and weight of each stick are known in advance. The sticks are to be processed by a woodworking machine in one by one fashion. It needs some time, called setup time, for the machine to prepare processing a stick. The setup times are associated with cleaning operations and changing tools and shapes in the machine. The setup times of the woodworking machine are given as follows:

(a) The setup time for the first wooden stick is 1 minute.
(b) Right after processing a stick of length l and weight w , the machine will need no setup time for a stick of length l' and weight w' if l<=l' and w<=w'. Otherwise, it will need 1 minute for setup.

You are to find the minimum setup time to process a given pile of n wooden sticks. For example, if you have five sticks whose pairs of length and weight are (4,9), (5,2), (2,1), (3,5), and (1,4), then the minimum setup time should be 2 minutes since there is a sequence of pairs (1,4), (3,5), (4,9), (2,1), (5,2).

 
 
Input
The input consists of T test cases. The number of test cases (T) is given in the first line of the input file. Each test case consists of two lines: The first line has an integer n , 1<=n<=5000, that represents the number of wooden sticks in the test case, and the second line contains n 2 positive integers l1, w1, l2, w2, ..., ln, wn, each of magnitude at most 10000 , where li and wi are the length and weight of the i th wooden stick, respectively. The 2n integers are delimited by one or more spaces.
 
 
Output
The output should contain the minimum setup time in minutes, one per line.
 
 
Sample Input
3 5 4 9 5 2 2 1 3 5 1 4 3 2 2 1 1 2 2 3 1 3 2 2 3 1
 
 
Sample Output
2 1 3
 两题一样.....

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