Game of Two Stacks


Problem Statement :


Alexa has two stacks of non-negative integers, stack A = [a0, a1, . . . , an-1 ] and stack B  = [b0, b1, . . . , b m-1]  where index 0 denotes the top of the stack. Alexa challenges Nick to play the following game:

In each move, Nick can remove one integer from the top of either stack A or stack B.
Nick keeps a running sum of the integers he removes from the two stacks.
Nick is disqualified from the game if, at any point, his running sum becomes greater than some integer  xgiven at the beginning of the game.
Nick's final score is the total number of integers he has removed from the two stacks.
Given A, B , and x for g games, find the maximum possible score Nick can achieve (i.e., the maximum number of integers he can remove without being disqualified) during each game and print it on a new line.


Output Format

For each of the g games, print an integer on a new line denoting the maximum possible score Nick can achieve without being disqualified.



Solution :



title-img


                            Solution in C :

In C ++ :






// author: gary
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

#define ALL(x) (x).begin(), x.end()

const int inf = 1e9;
const int maxn = 1e5 + 10;

ll a[maxn];
ll b[maxn];
int T, n, m, x;

int main() {
  scanf("%d", &T);
  while(T--) {
    scanf("%d%d%d", &n, &m, &x);
    for(int i = 1; i <= n; i++) scanf("%lld", a + i);
    for(int i = 1; i <= m; i++) scanf("%lld", b + i);

    for(int i = 1; i <= n; i++) a[i] += a[i-1];
    for(int i = 1; i <= m; i++) b[i] += b[i-1];

    int res = 0;
    for(int i = 0, j = m; i <= n && a[i] <= x; i++) {
      while(a[i] + b[j] > x && j >= 1)
        j --;
      res = max(res, i + j);
    }
    printf("%d\n", res);
  }
  return 0;
}









In Java :





import java.io.*;
import java.util.StringTokenizer;


public class Main {
    private void solve() {
        int t = rw.nextInt();
        for (int t_id = 0; t_id < t; ++t_id) {
            int n = rw.nextInt();
            int m = rw.nextInt();
            int x = rw.nextInt();
            int[] a = new int[n];
            int[] b = new int[m];
            for (int i = 0; i < n; ++i)
                a[i] = rw.nextInt();

            for (int i = 0; i < m; ++i)
                b[i] = rw.nextInt();

            int sum = 0;
            int c1 = 0;
            for (; c1 < n; ) {
                if (sum + a[c1] <= x) {
                    sum += a[c1];
                    ++c1;
                } else
                    break;
            }
            int c2 = 0;
            for (; c2 < m; ) {
                if (sum + b[c2] <= x) {
                    sum += b[c2];
                    ++c2;
                } else
                    break;
            }
            int ans = c1 + c2;
            for (; c1 > 0; --c1) {
                sum -= a[c1 - 1];
                while (c2 < m) {
                    if (sum + b[c2] <= x) {
                        sum += b[c2];
                        ++c2;
                    } else
                        break;
                }
                ans = Math.max(ans, c1 - 1 + c2);
            }

            rw.println(ans);
        }

    }

    private RW rw;
    private String FILE_NAME = "file";

    public static void main(String[] args) {
        new Main().run();
    }

    private void run() {
        rw = new RW(FILE_NAME + ".in", FILE_NAME + ".out");
        solve();
        rw.close();
    }

    private class RW {
        private StringTokenizer st;
        private PrintWriter out;
        private BufferedReader br;
        private boolean eof;

        RW(String inputFile, String outputFile) {
            br = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(new OutputStreamWriter(System.out));

            File f = new File(inputFile);
            if (f.exists() && f.canRead()) {
                try {
                    br = new BufferedReader(new FileReader(inputFile));
                    out = new PrintWriter(new FileWriter(outputFile));
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        private String nextLine() {
            String s = "";
            try {
                s = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return s;
        }

        private String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    eof = true;
                    return "-1";
                }
            }
            return st.nextToken();
        }

        private long nextLong() {
            return Long.parseLong(next());
        }

        private int nextInt() {
            return Integer.parseInt(next());
        }

        private void println() {
            out.println();
        }

        private void println(Object o) {
            out.println(o);
        }

        private void print(Object o) {
            out.print(o);
        }

        private void close() {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            out.close();
        }
    }
}










In C :



#include <stdio.h>

int main() {
    long long int c, i, g, m, n, x, la, lb;
    long long int a[100010], b[100010];
    scanf("%lld", &g);
    while (g--) {
        la = lb = 0;
        scanf("%lld%lld%lld", &n, &m, &x);
        scanf("%lld", &a[1]);
        for (i = 1; ++i <= n;) {
            scanf("%lld", &a[i]);
            a[i] += a[i - 1];
        }
        scanf("%lld", &b[1]);
        for (i = 1; ++i <= m;) {
            scanf("%lld", &b[i]);
            b[i] += b[i - 1];
        }
        la = 1;
        while (la <= n && a[la] <= x)
            la++;
        la--;
        c = la;
        lb = 1;
        while (lb <= m && b[lb] <= x) {
            if (la && b[lb] + a[la] > x)
                la--;
            else {
                if (c < la + lb)
                    c = la + lb;
                lb++;
            }
        }
        printf("%lld\n", c);
    }
    return 0;
}









In Python3 :




#!/bin/python3

import sys


g = int(input().strip())
for a0 in range(g):
    n,m,x = input().strip().split(' ')
    n,m,x = [int(n),int(m),int(x)]
    a = list(map(int, input().strip().split(' ')))
    b = list(map(int, input().strip().split(' ')))
    
    i = 0
    while i < len(a) and x >= a[i]:
        x -= a[i]
        i += 1
    
    ans = i
    j = 0
    for p in b:
        j += 1
        x -= p
        
        while x < 0 and i > 0:
            i -= 1
            x += a[i]
        
        if x >= 0: ans = max(ans, j + i)
    
    print(ans)
                        








View More Similar Problems

Dynamic Array

Create a list, seqList, of n empty sequences, where each sequence is indexed from 0 to n-1. The elements within each of the n sequences also use 0-indexing. Create an integer, lastAnswer, and initialize it to 0. There are 2 types of queries that can be performed on the list of sequences: 1. Query: 1 x y a. Find the sequence, seq, at index ((x xor lastAnswer)%n) in seqList.

View Solution →

Left Rotation

A left rotation operation on an array of size n shifts each of the array's elements 1 unit to the left. Given an integer, d, rotate the array that many steps left and return the result. Example: d=2 arr=[1,2,3,4,5] After 2 rotations, arr'=[3,4,5,1,2]. Function Description: Complete the rotateLeft function in the editor below. rotateLeft has the following parameters: 1. int d

View Solution →

Sparse Arrays

There is a collection of input strings and a collection of query strings. For each query string, determine how many times it occurs in the list of input strings. Return an array of the results. Example: strings=['ab', 'ab', 'abc'] queries=['ab', 'abc', 'bc'] There are instances of 'ab', 1 of 'abc' and 0 of 'bc'. For each query, add an element to the return array, results=[2,1,0]. Fun

View Solution →

Array Manipulation

Starting with a 1-indexed array of zeros and a list of operations, for each operation add a value to each of the array element between two given indices, inclusive. Once all operations have been performed, return the maximum value in the array. Example: n=10 queries=[[1,5,3], [4,8,7], [6,9,1]] Queries are interpreted as follows: a b k 1 5 3 4 8 7 6 9 1 Add the valu

View Solution →

Print the Elements of a Linked List

This is an to practice traversing a linked list. Given a pointer to the head node of a linked list, print each node's data element, one per line. If the head pointer is null (indicating the list is empty), there is nothing to print. Function Description: Complete the printLinkedList function in the editor below. printLinkedList has the following parameter(s): 1.SinglyLinkedListNode

View Solution →

Insert a Node at the Tail of a Linked List

You are given the pointer to the head node of a linked list and an integer to add to the list. Create a new node with the given integer. Insert this node at the tail of the linked list and return the head node of the linked list formed after inserting this new node. The given head pointer may be null, meaning that the initial list is empty. Input Format: You have to complete the SinglyLink

View Solution →