Submission #516124

#	Time	Username	Problem	Language	Result	Execution time	Memory
516124		Jeff12345121	Pinball (JOI14_pinball)	C++14	100 / 100	980 ms	53228 KiB

pinball

#include <bits/stdc++.h>
#define ll long long
#define int long long
using namespace std;

#ifdef EVAL
#define in cin
#define out cout
#else
ifstream in("in.in");
ofstream out("out.out");
#endif

int n, m;
const ll inf = (1LL << 60);
struct Dev {
    int l, r, hole, cost;
};
vector<Dev> dev;

struct SegTree {
    vector<int> v;
    int N;
    SegTree(int l, int r) : N(r + 1), v(5 * r + 1, inf) {}
    SegTree() {}

   private:
    void update(int ind, int l, int r, int qpos, int newVal) {
        if (qpos == l && qpos == r) {
            v[ind] = min(v[ind], newVal);
            return;
        }

        int mij = (l + r) / 2;
        if (qpos <= mij) {
            update(2 * ind, l, mij, qpos, newVal);
        } else {
            update(2 * ind + 1, mij + 1, r, qpos, newVal);
        }
        v[ind] = min(v[2 * ind], v[2 * ind + 1]);
    }

    int query(int ind, int l, int r, int ql, int qr) {
        if (ql <= l && r <= qr) {
            return v[ind];
        }

        int mij = (l + r) / 2, opt1 = inf, opt2 = inf;
        if (ql <= mij) {
            opt1 = query(2 * ind, l, mij, ql, qr);
        }
        if (qr >= mij + 1) {
            opt2 = query(2 * ind + 1, mij + 1, r, ql, qr);
        }
        return min(opt1, opt2);
    }

   public:
    void update(int pos, int newVal) {
        update(1, 1, N, pos, newVal);
    }
    int query(int l, int r) {
        return query(1, 1, N, l, r);
    }
};

SegTree segTreeLeft, segTreeRight;

template <typename F>
void getDp(vector<ll> &dp, F f) {
    /// we want to have all the pinballs take it past left
    // dp[i] = minCost to get all balls to this device
    segTreeLeft = SegTree(1, n);
    dp.resize(m + 1);
    for (int i = 1; i <= m; i++) {
        dp[i] = inf;
    }
    ll ans = inf;
    for (int i = 1; i <= m; i++) {
        if (f(dev[i])) {
            dp[i] = dev[i].cost;
        }
        dp[i] = min(dp[i], dev[i].cost + segTreeLeft.query(dev[i].l, dev[i].r));
        segTreeLeft.update(dev[i].hole, dp[i]);
    }
}
set<int> values;
map<int, int> valToNorm;
int32_t main() {
    in >> m >> n;
    /// m is number of lines, n is number of collumns

    vector<pair<int, int>> sortDev;
    sortDev.resize(m + 1);
    dev.resize(m + 1);
    for (int i = 1; i <= m; i++) {
        int l, r, hole, cost;
        in >> l >> r >> hole >> cost;
        values.insert(l);
        values.insert(r);
        values.insert(hole);
        dev[i] = {l, r, hole, cost};

        sortDev[i] = {l, r};
    }

    sort(sortDev.begin(), sortDev.end());

    {
        int r = 1;
        for (int i = 1; i <= m; i++) {
            if (sortDev[i].first > r) {
                out << "-1\n";
                return 0;
            }
            r = max(r, sortDev[i].second);
        }

        if (r < n) {
            out << "-1\n";
            return 0;
        }
    }

    sortDev.clear();

    int nr = 0;
    for (auto k : values) {
        valToNorm[k] = ++nr;
    }

    for (int i = 1; i <= m; i++) {
        dev[i].l = valToNorm[dev[i].l];
        dev[i].r = valToNorm[dev[i].r];
        dev[i].hole = valToNorm[dev[i].hole];
    }

    valToNorm.clear();
    values.clear();

    n = nr;

    vector<ll> leftDp, rightDp;
    getDp(leftDp, [&](Dev x) {
        return x.l == 1;
    });

    getDp(rightDp, [&](Dev x) {
        return x.r == n;
    });

    segTreeLeft = SegTree(1, n);
    segTreeRight = SegTree(1, n);
    ll ans = inf;
    for (int i = 1; i <= m; i++) {
        /// i is middle
        ll leftCost = inf, rightCost = inf;
        if (dev[i].l > 1) {
            leftCost = segTreeLeft.query(dev[i].l, dev[i].r);
        } else {
            leftCost = 0;
        }

        if (dev[i].r < n) {
            rightCost = segTreeRight.query(dev[i].l, dev[i].r);
        } else {
            rightCost = 0;
        }

        segTreeLeft.update(dev[i].hole, leftDp[i]);
        segTreeRight.update(dev[i].hole, rightDp[i]);

        ans = min(ans, leftCost + rightCost + dev[i].cost);
        // cout << "\n";
    }

    if (ans == inf) {
        out << "-1\n";
    } else {
        out << ans << "\n";
    }
}

Compilation message (stderr)

pinball.cpp: In constructor 'SegTree::SegTree(long long int, long long int)':
pinball.cpp:23:9: warning: 'SegTree::N' will be initialized after [-Wreorder]
   23 |     int N;
      |         ^
pinball.cpp:22:17: warning:   'std::vector<long long int> SegTree::v' [-Wreorder]
   22 |     vector<int> v;
      |                 ^
pinball.cpp:24:5: warning:   when initialized here [-Wreorder]
   24 |     SegTree(int l, int r) : N(r + 1), v(5 * r + 1, inf) {}
      |     ^~~~~~~
pinball.cpp: In instantiation of 'void getDp(std::vector<long long int>&, F) [with F = main()::<lambda(Dev)>]':
pinball.cpp:146:6:   required from here
pinball.cpp:78:8: warning: unused variable 'ans' [-Wunused-variable]
   78 |     ll ans = inf;
      |        ^~~
pinball.cpp: In instantiation of 'void getDp(std::vector<long long int>&, F) [with F = main()::<lambda(Dev)>]':
pinball.cpp:150:6:   required from here
pinball.cpp:78:8: warning: unused variable 'ans' [-Wunused-variable]

• Subtask 1: 11 / 11
• Subtask 2: 18 / 18
• Subtask 3: 22 / 22
• Subtask 4: 49 / 49