【刷题】【dp】 Make The Fence Great Again

二维dp

%%%%大佬，最近没啥时间写博客了，以后补上

https://www.cnblogs.com/bianjunting/p/11556876.html

 

结果最后tle靠快读卡过去了

#include<cstdio>
#include<cstdlib>
#include<iostream>
using namespace std;
#define ll long long
int n;
const int N=3e5+10;
ll f[N][3];

inline ll read()
{
    ll x=0;char c=getchar();
    while(c< '0' || c> '9' ) c=getchar();
    while(c>='0' && c<='9' ) x=(x<<3)+(x<<1)+c-'0',c=getchar();
    return x;
}

int main()
{
    int q;q=read();
    while(q--)
    {
        n=read();
        ll pre,now=read(),v=read(); 
        f[1][1]=v,f[1][2]=(v<<1);
        
        for(int i=2;i<=n;i++)
        {
            pre=now;
            now=read(),v=read();
            f[i][0]=f[i][1]=f[i][2]=-1;
            
            for(int j=0;j<3;j++)
                for(int k=0;k<3;k++)
                {
                    if((pre+j) != (now+k) )
                        if(f[i][k]==-1 ) f[i][k]=f[i-1][j]+v*k;
                        else f[i][k]=min(f[i][k],f[i-1][j]+v*k);
                }
        }
        
        cout<<min(f[n][0],min(f[n][1],f[n][2] ) )<<endl;
    }
    
    return 0;
}