1346. Intervals of Monotonicity（ｄｐ）

１３４６

简单ｄｐ

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 #include<vector>
 using namespace std;
 #define N 200010
 int p[N],dp[N][];
 int main()
 {
     int i,a,b;
     scanf("%d%d",&a,&b);
     for(i =  ; i <= b-a+ ; i++)
     scanf("%d",&p[i]);
     dp[][] = ;
     dp[][] = ;
     for(i = ; i <= b-a+ ; i++)
     {
         if(p[i]>p[i-])
         {
             dp[i][] = min(dp[i-][]+,dp[i-][]);
             dp[i][] = min(dp[i-][]+,dp[i-][]+);
         }
         else if(p[i]<p[i-])
         {
             dp[i][] = min(dp[i-][]+,dp[i-][]+);
             dp[i][] = min(dp[i-][]+,dp[i-][]);
         }
         else
         {
             dp[i][] = min(dp[i-][],dp[i-][]+);
             dp[i][] = min(dp[i-][],dp[i-][]+);
         }
     }
     int ans = min(dp[b-a+][],dp[b-a+][]);
     printf("%d\n",ans);
     return ;
 }