PKUOJ1065 Wooden Sticks

Wooden Sticks
Time Limit:1000MS
Memory Limit:10000K
Total Submissions:11794
Accepted:4808
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 ( 9 , 4 ) , ( 2 , 5 ) , ( 1 , 2 ) , ( 5 , 3 ) , and ( 4 , 1 ) , then the minimum setup time should be 2 minutes since there is a sequence of pairs ( 4 , 1 ) , ( 5 , 3 ) , ( 9 , 4 ) , ( 1 , 2 ) , ( 2 , 5 ) .
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 2n 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

【 】

n개의 막대기가 있는데, 각 막대기는 길이와 무게가 다르다.한 대의 기계로 이 막대기들을 처리하면 i+1개의 막대기의 길이>=i개의 막대기의 길이&&&i+1개의 막대기의 무게>=i개의 막대기의 무게를 처리할 때 기계가 막대기를 처리하는 단위 시간 setup time에 1을 더하여 n개의 막대기를 처리하는 데 필요한 최소 시간을 구한다

【 】

막대기의 길이에 따라 작은 것부터 큰 것까지 순서를 정하고, 막대기의 길이가 같을 때 무게에 따라 작은 것부터 큰 것까지 순서를 정한다.그리고 현재 길이보다 큰 막대기(이미 막대기에 대해 정렬을 하였으며, 매번 선택은 뒤에 영향을 가장 적게 미친다)를 순서대로 선택하여 선택한 막대기에 표시한다.한 바퀴 후, setup time+1, 그리고 남은 나무 막대기를 선택하면 가장 좋은 결과를 얻을 수 있습니다.
#include
using namespace std;
struct wood
{
int l;
int w;
}st[5005];
int work(int m)
{
int temp;
int sum=0;
for (int i =0;i{
if (st[i].w!=-1)
{
temp = st[i].w;
sum++;
for (int j=i+1;j{
if (st[j].w>=temp)
{
temp=st[j].w;
st[j].w=-1;
}
}
}
}
return sum;
}
//비교 함수
int cmp(const void *a ,const void *b)
{
if((*(wood *)a).l==(*(wood*)b).l)
return (*(wood *)a).w -(*(wood *)b).w;
return (*(wood *)a).l - (*(wood *)b).l;
}
int main()
{
int n,m;
cin>>n;
while (n--)
{
cin>>m;
for (int i=0;i{
cin>>st[i].l>>st[i].w;
}
qsort(st,m,sizeof(st[0]),cmp);
cout<}
return 0;
}