Submission #544325

#	Time	Username	Problem	Language	Result	Execution time	Memory
544325		SmolBrain	Automobil (COCI17_automobil)	C++17	100 / 100	28 ms	23804 KiB

automobil

// Om Namah Shivaya
// GM in 123 days

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}

void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}
template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }

void usaco(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}

const int MOD = 1e9 + 7;
const int maxn = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;

void solve(int test_case)
{
    /*

    https://ideone.com/Ejf10T => though my sol idea is not similar to this code,
    i got the ideas for building the sol from this code


    sol idea: initially do all the row operations, then modify the column sum 'colsum' values and then do the column operations

    val = the initial value written on a given cell
    colsum[j] = sum of all cells in column j, initially stores the sum of all the initial values written on the cells in column j

    modifying the 'colsum' array: colsum[j] - val + val * rowmul[i] = colsum[j] + val * (rowmul[i] - 1)

    when moving from col to col + 1, the summation of val * (rowmul[i] - 1) over all i
    increases by 'sum', where sum = the sum of (rowmul[i] - 1) over all i
    this is because the value 'val' of all cells increase by 1 when u go from col to col + 1
    (val + 1) * (rowmul[i] - 1) - val * (rowmul[i] - 1) = rowmul[i] - 1

    */

    ll n, m, k; cin >> n >> m >> k;

    vector<ll> rowmul(n + 5, 1), colmul(m + 5, 1);

    rep1(i, k) {
        char ch; cin >> ch;
        ll x, y; cin >> x >> y;

        if (ch == 'R') rowmul[x] = (rowmul[x] * y) % MOD;
        else colmul[x] = (colmul[x] * y) % MOD;
    }

    auto get = [&](ll i, ll j) {
        return ((i - 1) * m + j) % MOD;
    };

    auto apsum = [&](ll a, ll d) {
        // 0.5n*(2a + (n - 1)d)
        ll res = n * (2 * a + (n - 1) * d);
        res /= 2;
        res %= MOD;
        return res;
    };

    vector<ll> colsum(m + 5);
    rep1(j, m) {
        colsum[j] = apsum(j, m);
    }

    ll sum = 0, curr = 0;
    rep1(i, n) {
        sum += rowmul[i] - 1;
        sum %= MOD;

        ll temp = (get(i, 1) * (rowmul[i] - 1) % MOD + MOD) % MOD;
        curr = (curr + temp) % MOD;
    }

    ll ans = 0;

    rep1(j, m) {
        colsum[j] = (colsum[j] + curr + MOD) % MOD;
        ll toadd = colsum[j] * colmul[j] % MOD;
        ans = (ans + toadd) % MOD;
        curr = (curr + sum) % MOD;
    }

    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;
    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message (stderr)

automobil.cpp: In function 'void usaco(std::string)':
automobil.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
automobil.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100