洛谷 P1020 导弹拦截

题目传送门

解题思路:

其实就是求一遍最长不上升子序列和最长上升子序列

AC代码:

 #include<iostream>
 #include<cstdio>
 #include<algorithm> 

 using namespace std;

 int n,a[],f[],dp[],len = ,tot = ,p;

 int main() {
     while(scanf("%d",&a[++p]) != EOF);
     f[] = a[];
     dp[] = a[];
     p--;
     for(int i = ;i <= p; i++) {
         if(a[i] <= f[len])
             f[++len] = a[i];
         else {
             int u = upper_bound(f+,f+len+,a[i],greater<int>()) - f;
             f[u] = a[i];
         }
         if(a[i] > dp[tot])
             dp[++tot] = a[i];
         else {
             int o = lower_bound(dp+,dp+tot+,a[i]) - dp;
             dp[o] = a[i];
         }
     }
     printf("%d\n%d",len,tot);
     return ;
 }