Atcoder Educational Dp contest :: C vacation

 

#include<bits/stdc++.h>
using namespace std;

#define ll long long

int const inf = 1e9+5;
int const mod = 1e9+7;

int main(){
    ll n;
    cin>>n;
    ll a[n],b[n],c[n];
    for(ll i=0;i<n;i++)cin>>a[i]>>b[i]>>c[i];
    ll dp[n][3];

    //base case

    dp[0][0] = a[0];
    dp[0][1] = b[0];
    dp[0][2] = c[0];

    //recursive case

    for(ll i=1;i<n;i++){
        dp[i][0] = a[i] + max(dp[i-1][1],dp[i-1][2]);
        dp[i][1] = b[i] + max(dp[i-1][0],dp[i-1][2]);
        dp[i][2] = c[i] + max(dp[i-1][0],dp[i-1][1]);
    }
    cout<<max({dp[n-1][0],dp[n-1][1],dp[n-1][2]});
    return 0;
}