C :

#include<stdio.h>
int N,x,y,Sum=1,k;
int main(){
	scanf("%d%d",&N,&x);
	for(int i=2;i<=N;i++){
		scanf("%d",&y);
		if(y>x){//升序k=1
			if(k==2||k==0){
				k=1;
				Sum++;
				x=y;
			}
			if(k==1)x=y;//取大
		}
		if(y<x){//降序k=2
			if(k==1||k==0){
				k=2;
				Sum++;
				x=y;
			}
			if(k==2)x=y;//取小
		}
	}
	printf("%d",Sum);
}

C++ :

#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

int N=0;
int nDate_A[1000001]={0},nDate_B[1000001]={0};
int nFlower[1000001]={0};
int nLen_A=1,nLen_B=1,maxx=0;

int main(){
	scanf("%d",&N);
	for(int i=1;i<=N;++i){
		scanf("%d",&nFlower[i]);
	}
	nDate_A[nLen_A]=nFlower[1];
	nDate_B[nLen_B]=nFlower[1];
	for(int i=2;i<=N;++i){//第A种
		if(nLen_A%2==1){
			if(nFlower[i]>nDate_A[nLen_A]) nDate_A[++nLen_A]=nFlower[i];
			else nDate_A[nLen_A]=nFlower[i];
		}
		else{
			if(nFlower[i]<nDate_A[nLen_A]) nDate_A[++nLen_A]=nFlower[i];
			else nDate_A[nLen_A]=nFlower[i];
		}
		
		if(nLen_B%2==1){
			if(nFlower[i]<nDate_B[nLen_B]) nDate_B[++nLen_B]=nFlower[i];
			else nDate_B[nLen_B]=nFlower[i];
		}
		else{
			if(nFlower[i]>nDate_B[nLen_B]) nDate_B[++nLen_B]=nFlower[i];
			else nDate_B[nLen_B]=nFlower[i];
		}
	}
	printf("%d",max(nLen_B,nLen_A));
	fclose(stdin);
	fclose(stdout);
	return 0;
}

Pascal :

var
 n,i,j,k:longint;
 a,b:array[1..100000] of longint;

begin
 k:=0;
 read(n);
 for i:=1 to n do read(a[i]);
 b[1]:=a[1];
 j:=1;
 for i:=2 to n do
  if a[i]<>b[j] then
   begin
    b[j+1]:=a[i];
    j:=j+1;
   end;
 for i:=2 to j-1 do
 if ((b[i]>b[i-1]) and (b[i]>b[i+1])) or ((b[i]<b[i-1]) and (b[i]<b[i+1])) then
  k:=k+1;
 write(k+2);
end.