Submission #1272397

#	Time	Username	Problem	Language	Result	Execution time	Memory
1272397		Art	Relativnost (COCI15_relativnost)	C++20	126 / 140	4093 ms	2492 KiB

relativnost

//      - Art -
#pragma GCC optimize("O3,unroll-loops") // O2
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>

#define el              cout << '\n'

#define FOR(i, a, b)    for (int i = (a), _b = (b); i <= _b; ++i)
#define REV(i, b, a)    for (int i = (b), _a = (a); i >= _a; --i)
#define REP(i, c)       for (int i = 0, _c = (c); i < _c; ++i)

const int N = 1e5 + 7;
const int MOD = 1e4 + 7;
const int BLOCKSIZE = 578;
const int NUMBLOCK = N / BLOCKSIZE + 7;

using namespace std;

int a[N], b[N];

namespace naive {
    int dp[N][22];

    void solve(int n, int k) {
        int q;
        cin >> q;
        while (q--) {
            int id, na, nb;
            cin >> id >> na >> nb;
            na %= MOD;
            nb %= MOD;
            a[id] = na;
            b[id] = nb;

            dp[0][0] = 1;
            FOR (i, 1, n) REP (j, k) {
                dp[i][j] = dp[i - 1][j] * b[i] % MOD;
                if (j > 0) {
                    dp[i][j] = (dp[i][j] + dp[i - 1][j - 1] * a[i]) % MOD;
                }
            }

            int tot = 1;
            FOR (i, 1, n) {
                tot = (a[i] + b[i]) * tot % MOD;
            }
            REP (i, k) {
                tot = (tot - dp[n][i] + MOD) % MOD;
            }
            cout << tot, el;
        }
    }
}

int block[N];
int dp[NUMBLOCK][22];
int pre[NUMBLOCK][22];

int main() {

    #define name "art"
    if (fopen(name".inp", "r")) {
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }

    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    auto inverse = [&](int a) -> int {
        int b = MOD - 2, res = 1;
        while (b) {
            if (b & 1) {
                res = res * a % MOD;
            }
            a = a * a % MOD;
            b >>= 1;
        }
        return res;
    };

    int n, k;
    cin >> n >> k;
    FOR (i, 1, n) {
        cin >> a[i];
        a[i] %= MOD;
    }
    FOR (i, 1, n) {
        cin >> b[i];
        b[i] %= MOD;
    }

    if (n <= 5000) {
        naive::solve(n, k);
        return 0;
    }

    int tot = 1;
    REP (i, n) {
        block[i] = i / BLOCKSIZE;
        a[i] = a[i + 1];
        b[i] = b[i + 1];
        tot = (a[i] + b[i]) * tot % MOD;
    }

    FOR (x, 0, block[n - 1]) {
        int l = x * BLOCKSIZE;
        int r = min(n, l + BLOCKSIZE) - 1;
        dp[x][0] = b[l];
        dp[x][1] = a[l];
        FOR (i, l + 1, r) REV (j, k - 1, 0) {
            dp[x][j] = (dp[x][j] * b[i]) % MOD;
            if (j > 0) {
                dp[x][j] = (dp[x][j] + dp[x][j - 1] * a[i]) % MOD;
            }
        }
        if (x > 0) {
            REP (j, k) REP (o, j + 1) {
                pre[x][j] = (pre[x][j] + pre[x - 1][o] * dp[x][j - o]) % MOD;
            }
        }
        else {
            REP (j, k) {
                pre[x][j] = dp[x][j];
            }
        }
    }

    int q;
    cin >> q;
    while (q--) {
        int id, na, nb;
        cin >> id >> na >> nb;
        na %= MOD;
        nb %= MOD;
        --id;
        tot = tot * inverse(a[id] + b[id]) % MOD;
        tot = tot * (na + nb) % MOD;
        a[id] = na;
        b[id] = nb;

        int x = block[id];
        int l = x * BLOCKSIZE;
        int r = min(n, l + BLOCKSIZE) - 1;
        memset(dp[x], 0, sizeof dp[x]);
        dp[x][0] = b[l];
        dp[x][1] = a[l];
        FOR (i, l + 1, r) {
            REV (j, k - 1, 0) {
                dp[x][j] = dp[x][j] * b[i] % MOD;
                if (j > 0) {
                    dp[x][j] = (dp[x][j] + dp[x][j - 1] * a[i]) % MOD;
                }
            }
        }

        int res = tot;
        for (; x <= block[n - 1]; ++x) {
            if (x > 0) {
                memset(pre[x], 0, sizeof pre[x]);
                REP (j, k) {
                    REP (o, j + 1) {
                        pre[x][j] = (pre[x][j] + pre[x - 1][o] * dp[x][j - o]) % MOD;
                    }
                }
            }
            else {
                REP (j, k) {
                    pre[x][j] = dp[x][j];
                }
            }
        }

        REP (j, k) {
            res = (res - pre[block[n - 1]][j] + MOD) % MOD;
        }
        cout << res, el;
    }

    cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << "s\n";

    return 0;
}

Compilation message (stderr)

relativnost.cpp: In function 'int main()':
relativnost.cpp:63:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
relativnost.cpp:64:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 126 / 140