USACO 2017 December Contest Bronze Division - Milk Measurement

Problem link: here

Solution Author: Stefan Dascalescu

Problem Solution

Simulate this using brute force and check the changes every time.

Source codes

The source codes in C++ and Python can be seen below.

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

int qt[3], delta[3][102];

int main()
{
    ifstream cin("measurement.in");
    ofstream cout("measurement.out");

    int n;
    cin >> n;

    int msk = 7; // bitmask with all cows
    for(int i = 1; i <= n; i++)
    {
        int d, cnt;
        string who;
        cin >> d >> who >> cnt;
        if(who[0] == 'B')
            delta[0][d] += cnt;
        if(who[0] == 'E')
            delta[1][d] += cnt;
        if(who[0] == 'M')
            delta[2][d] += cnt;
    }
    int ans = 0;
    for(int i = 1; i <= 100; i++)
    {
        for(int j = 0; j <= 2; j++)
            qt[j] += delta[j][i];
        int mx2 = max(qt[0], max(qt[1], qt[2]));
        int msk2 = 4 * (qt[0] == mx2) + 2 * (qt[1] == mx2) + (qt[2] == mx2);
        ans += (msk != msk2);
        msk = msk2;
    }

    cout << ans;
    return 0;
}

with open("measurement.in", "r") as fin:
    n = int(fin.readline().strip())
    delta = [[0] * 102 for _ in range(3)]
    qt = [0, 0, 0]
    msk = 7  # bitmask with all cows

    for _ in range(n):
        parts = fin.readline().split()
        d = int(parts[0])
        who = parts[1]
        cnt = int(parts[2])
        if who[0] == 'B':
            delta[0][d] += cnt
        if who[0] == 'E':
            delta[1][d] += cnt
        if who[0] == 'M':
            delta[2][d] += cnt

ans = 0
for i in range(1, 101):
    for j in range(3):
        qt[j] += delta[j][i]
    mx2 = max(qt[0], qt[1], qt[2])
    msk2 = (4 if qt[0] == mx2 else 0) + (2 if qt[1] == mx2 else 0) + (1 if qt[2] == mx2 else 0)
    if msk != msk2:
        ans += 1
    msk = msk2

with open("measurement.out", "w") as fout:
    fout.write(str(ans))