SGU-133-Border (simple statistics)

SGU-133-Border (simple statistics)

133. Border

Time limit per test: 0.25 sec.
Memory limit per test: 4096 KB

Along the border between statesAAndBThere areNDefense outposts. For every outpostK, The interval[Ak, Bk]Which is guarded by it is known. Because of financial reasons, the president of countryADecided that some of the outposts shoshould be abandoned. In fact, all the redundant outposts will be abandoned. An outpostIIs redundant if there exists some outpostJSuch thatAjiAndBi . Your task is to find the number of redundant outposts.

Input

The first line of the input will contain in the integer numberN(1 <= N <= 16 000).NLines will follow, each of them containing2Integers:AkAndBk(0 <= Ak <Bk <= 2 000 000 000), Separated by blanks. All the numbersAkWill be different. All the numbersBkWill be different.

Output

You shoshould print the number of redundant outposts.

Sample Input

50 102 93 81 156 11

Sample Output

3

Author	: Mugurel Ionut Andreica
Resource	: SSU: Online Contester Fall Contest #2
Date	: Fall 2002

Train of Thought: sort the integer pairs in ascending order of the first value, and traverse them later. If the second value of each operation is smaller than the maximum value of the second value, ans ++, note that do not add EOF, Will PE

AC code:

#include 
  
   #include 
   
    #include #include 
    
     using namespace std;struct node {int x, y;}a[16005];int N;bool cmp(node a, node b) {return a.x < b.x;}int main() {scanf("%d", &N);for(int i = 0; i < N; i++) {scanf("%d %d", &a[i].x, &a[i].y);}sort(a, a + N, cmp);int ans = 0;int MAX = a[0].y;for(int i = 1; i < N; i++) {if(a[i].y < MAX) ans ++;else MAX = a[i].y;}printf("%d\n", ans);return 0;}