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).
(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
/************************************************************************************************************* 题意：有n木棒，给出长度和重量，首先setup耗时+1 如果i+1根木棒的长度和重量均小于i 则不耗时 否则重新setup time 耗时+1 求出最少的setup time 思路：首先按关键字进行排序 然后遍历找出符合条件的元素 *************************************************************************************************************/ #include <cstdio> #include <algorithm> #include <cstring> using namespace std; typedef struct { int l; int w; }st; st a[5000+10]; bool flag[5000+10]; bool cmp(st x , st y) { if(x.l == y.l) return x.w < y.w; return x.l < y.l; } int main() { //freopen("data.in", "r", stdin); //freopen("data.out", "w", stdout); int t; scanf("%d", &t); while(t--) { memset(flag , false , sizeof(flag)); int n; 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 ans = 0; for(int i = 0 ; i < n ; i ++) { if(flag[i]) continue; st temp = a[i]; ans++; for(int j = i + 1; j < n ; j++) { if(a[j].l <= temp.l && a[j].w <= temp.w && !flag[j]) { flag[j] = true; temp = a[j]; } } } printf("%d " , ans); } return 0; }