2.cpp

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

int main()
{
    int t;
    scanf("%d", &t);
    while(t--) {
        int n;
        scanf("%d", &n);
        int costs[n][3];
        for(int i=0;i<n;i++)
            scanf("%d %d %d", &costs[i][0], &costs[i][1], &costs[i][2]);
        int min_cost = 99999999;
        int dp[n][3];
        dp[0][0] = costs[0][0];
        dp[0][1] = costs[0][1];
        dp[0][2] = costs[0][2];
        for(int i=1;i<n;i++)
        {
            dp[i][0] = costs[i][0] + min(dp[i-1][1], dp[i-1][2]);
            dp[i][1] = costs[i][1] + min(dp[i-1][0], dp[i-1][2]);
            dp[i][2] = costs[i][2] + min(dp[i-1][1], dp[i-1][0]);
        }
        min_cost = min(dp[n-1][0], dp[n-1][1]);
        min_cost = min(min_cost, dp[n-1][2]);
        printf("%d\n", min_cost);
    }
}