DynamicProgrammingStriver/NinjaTrainingLecture7.cpp at main · dhruvkej9/DynamicProgrammingStriver · GitHub

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#include <iostream>
#include <vector>
using namespace std;
// Ninja training
int solve1(int day,int last,vector<vector<int>> &points)
{
    if(day == 0)
    {
        int maxi = 0;
        for(int task = 0;task < 3;task++)
        {
            if(task != last) maxi = max(maxi,points[0][task]);
        }
        return maxi;
    }

    int maxi = 0;

    for(int task = 0;task < 3;task++)
    {
        if(task != last)
        {
            int point = points[day][task] + solve1(day-1,task,points);
            maxi = max(maxi,point);
        }
    }
    return maxi;
}
int solve2(int day,int last,vector<vector<int>> &points,vector<vector<int>> &dp)
{
    if(day == 0)
    {
        int maxi = 0;
        for(int task = 0;task < 3;task++)
        {
            if(task != last) maxi = max(maxi,points[0][task]);
        }
        return maxi;
    }
    if(dp[day][last] != -1) return dp[day][last];

    int maxi = 0;

    for(int task = 0;task < 3;task++)
    {
        if(task != last)
        {
            int point = points[day][task] + solve2(day-1,task,points,dp);
            maxi = max(maxi,point);
        }
    }
    return dp[day][last] = maxi;
}
int solve3(int n, vector<vector<int>> &points,vector<vector<int>> &dp)
{
    dp[0][0] = max(points[0][1],points[0][2]);
    dp[0][1] = max(points[0][0],points[0][2]);
    dp[0][2] = max(points[0][0],points[0][1]);
    dp[0][3] = max(points[0][0],max(points[0][1],points[0][2]));

    for(int day = 1;day < n;day++)
    {
        for(int last = 0;last < 4;last++)
        {
            dp[day][last] = 0;
            for(int task = 0;task < 3;task++)
            {
                if(task != last && (last != 3 || day == n-1))
                {
                    int point = points[day][task] + dp[day-1][task];
                    dp[day][last] = max(dp[day][last],point);
                }
            }
        }
    }
    return dp[n-1][3];
}
int solve4(int n, vector<vector<int>> &points)
{
    vector<int> prev(4,0);
    prev[0] = max(points[0][1],points[0][2]);
    prev[1] = max(points[0][0],points[0][2]);
    prev[2] = max(points[0][0],points[0][1]);
    prev[3] = max(points[0][0],max(points[0][1],points[0][2]));

     for(int day = 1;day < n;day++)
    {   vector<int> temp(4,0);
        for(int last = 0;last < 4;last++)
        {
            temp[last] = 0;
            for(int task = 0;task < 3;task++)
            {
                if(task != last && (last != 3 || day == n-1))
                {
                    int point = points[day][task] + prev[task];
                    temp[last] = max(temp[last],point);
                }
            }
        }
        prev = temp;
    }
    return prev[3];
}
int ninjaTraining(int n, vector<vector<int>> &points)
{
    vector<vector<int>> dp(n,vector<int>(4,-1));
    // return solve1(n-1,3,points); // Recursion
    // return solve2(n-1,3,points,dp); // Memoization
    // return solve3(n,points,dp); // Tabulation
    // return solve4(n,points); // Space Optimization
}