- Wooden Sticks

C - Wooden Sticks

Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u

Submit Status

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

#include<stdio.h>#include<string.h>#include<iostream>#include<algorithm>using namespace std;struct node{int l,w;};node a[5010];int f[5010];int cmp(node n1,node n2){return n1.l!=n2.l?n1.l>n2.l:n1.w>n2.w;}int main(){int t,n;memset(a,-1,sizeof(a));memset(f,0,sizeof(f));scanf("%d",&t);while(t--){scanf("%d",&n);for(int i=0; i<n; i++){scanf("%d%d",&a[i].l,&a[i].w);}sort(a,a+n,cmp);int len = 1;f[len] = a[0].w;for(int i=1; i<n; i++){if(a[i].w>f[len]){f[++len] = a[i].w;}else{int tmp = lower_bound(f,f+len,a[i].w)-f;f[tmp] = a[i].w;}}printf("%d\n",len);}return 0;}