tyvj1106 登山

/*
每一次它都可以朝左、右、左上、右上四个方向走

！！！！！！！！！！！！！！！！

每一次它都可以朝左、右、左上、上四个方向走

不是右上是上！！！！！！！！！！！！！！！！
*/

#include<iostream>
#include<cstdio>
#include<string>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn = 987654321;
int n,h[1050][1050],dp[1050][1050];
int main(){
    cin>>n;
    for(int i = 1;i <= n;i++){
        for(int j = 1;j <= i;j++){
            scanf("%d",&h[i][j]);
         }
    }
    for(int i = 0;i <= n + 1;i++){
        for(int j = 0;j <= 1000;j++){
            dp[i][j] = maxn;
        }
    }
    dp[n][1] = 0;
    for(int i = n;i >= 1;i--){
        for(int j = 1;j <= i;j++){
            if(j == 1) dp[i][j] = min(min(dp[i][j],dp[i+1][j] + h[i+1][j]),min(dp[i+1][i+1] + h[i+1][i+1],dp[i+1][j+1] + h[i+1][j+1]));
            else if(j == i) dp[i][j] = min(dp[i][j],min(dp[i+1][1] + h[i+1][1],min(dp[i+1][j+1] + h[i+1][j+1],dp[i+1][j] + h[i+1][j])));
            else dp[i][j] = min(dp[i][j],min(dp[i+1][j+1] + h[i+1][j+1],dp[i+1][j] + h[i+1][j]));
        }
        dp[i][1] = min(dp[i][1],dp[i][i] + h[i][i]);
        for(int j = 2;j <= i;j++) dp[i][j] = min(dp[i][j],dp[i][j-1] + h[i][j-1]);
        dp[i][n] = min(dp[i][n],dp[i][1] + h[i][1]);
        for(int j = n - 1;j >= 1;j--) dp[i][j] = min(dp[i][j],dp[i][j+1] + h[i][j+1]);
    }
    cout<<dp[1][1] + h[1][1];
    return 0;
}