Submission #1085976

#	Time	Username	Problem	Language	Result	Execution time	Memory
1085976		RiverFlow	Railway Trip 2 (JOI22_ho_t4)	C++14	27 / 100	2087 ms	51028 KiB

Main

#include <bits/stdc++.h>

#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())

using namespace std;

template<typename U, typename V> bool maxi(U &a, V b) {
    if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
    if (a > b or a == -1) { a = b; return 1; } return 0;
}

const int N = (int)2e5 + 9;
const int mod = (int)1e9 + 7;

void prepare(); void main_code();

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    const bool MULTITEST = 0; prepare();
    int num_test = 1; if (MULTITEST) cin >> num_test;
    while (num_test--) { main_code(); }
}

void prepare() {};

int n, k, m, q;
int a[N], b[N];
pair<int, int> Q[N];

namespace SUB1 {
const int N = 307;

int d[N][N];

void sol() {
    memset(d, -1, sizeof d);
    FOR(i, 1, m) {
        if (a[i] < b[i]) {
            FOR(j, a[i], min(a[i] + k - 1, b[i] - 1))
            FOR(t, j + 1, b[i])
                d[j][t] = 1;
        } else {
            FOD(j, a[i], max(a[i] - k + 1, b[i] + 1))
            FOD(t, j - 1, b[i])
                d[j][t] = 1;
        }
    }
    FOR(k, 1, n)
    FOR(i, 1, n) if (d[i][k] != -1)
    FOR(j, 1, n) if (d[k][j] != -1) {
        mini(d[i][j], d[i][k] + d[k][j]);
    }
    FOR(i, 1, q) cout << d[Q[i].fi][Q[i].se] << nl;
}
};


int l[N], r[N], d[N];
vector<int> insmax[N], revmax[N], insmin[N], revmin[N];

void buildLR() {
    FOR(i, 1, n) l[i] = n + 1;
    FOR(i, 1, m) {
        if (a[i] < b[i]) {
            insmax[a[i]].push_back(b[i]);
            revmax[min(a[i] + k - 1, b[i] - 1)].push_back(b[i]);
        } else {
            insmin[a[i]].push_back(b[i]);
            revmin[max(a[i] - k + 1, b[i] + 1)].push_back(b[i]);
        }
    }
    multiset<int> v;
    FOR(i, 1, n) {
        for(int j : insmax[i]) {
            v.insert(j);
        }
        if (sz(v)) r[i] = *v.rbegin();
        for(int j : revmax[i]) {
            v.erase(v.find(j));
        }
    }
    FOD(i, n, 1) {
        for(int j : insmin[i]) {
            v.insert(j);
        }
        if (sz(v)) l[i] = *v.begin();
        for(int j : revmin[i]) {
            v.erase(v.find(j));
        }
    }
}
namespace SUB2 {
void sol() {
    FOR(i, 1, q) {
        queue<int> f;
        int x = Q[i].fi, y = Q[i].se;
        int L = x, R = x;
        FOR(i, 1, n) d[i] = -1;
        d[x] = 0;
        f.push(x);
        while (!f.empty()) {
            int u = f.front(); f.pop();
            if (u == y) break ;
            if (l[u] < L) {
                FOR(j, l[u], L - 1) {
                    d[j] = d[u] + 1;
                    f.push(j);
                }
                L = l[u];
            }
            if (r[u] > R) {
                FOR(j, R + 1, r[u]) {
                    d[j] = d[u] + 1;
                    f.push(j);
                }
                R = r[u];
            }
        }
        cout << d[y] << nl;
    }
}
};

namespace SUB4 {
const int LG = 17;
int sp[N][LG + 1], jmp[N][LG + 1], lg[N + 1];
int get(int x, int y) {
    int j = lg[y - x + 1];
    x = sp[x][j], y = sp[y - (1 << j) + 1][j];
    return (r[x] > r[y] ? x : y);
}
int cmp(int x, int y) {
    return (r[x] > r[y] ? x : y);
}
void sol() {
    FOR(i, 1, n) {
        r[i] = max(r[i], i);
        sp[i][0] = i;
        if (i > 1) lg[i] = lg[i / 2] + 1;
    }
    for(int j = 1; (1 << j) <= n; ++j)
        for(int i = 1; i + (1 << j) - 1 <= n; ++i)
            sp[i][j] = cmp(sp[i][j - 1], sp[i + (1 << (j - 1))][j - 1]);

    memset(jmp, -1, sizeof jmp);

    FOR(i, 1, n) {
        if (i == r[i]) {
            continue ;
        }
        int nxt = get(i + 1, r[i]);
        jmp[i][0] = nxt;
        FOR(j, 1, LG) {
            int p = jmp[ jmp[i][j - 1] ][j - 1];
            if (p == -1) break ;
            jmp[i][j] = p;
        }
    }
    FOR(i, 1, q) {
        int x = Q[i].fi, y = Q[i].se;
        int ans = 0;
        FOD(i, LG, 0) if (jmp[x][i] != -1 and r[jmp[x][i]] < y) {
            ans += (1 << i);
            x = jmp[x][i];
        }
        while (r[x] < y) {
            ++ans;
            if (x == r[x]) {
                ans = -1; break ;
            }
            x = get(x + 1, r[x]);
        }
        if (ans == -1) {
            cout << -1 << nl;
            continue ;
        }
        if (r[x] < y) cout << -1 << nl;
        else          cout << ans + (x != y) << nl;
    }
}
};

void main_code() {
    cin >> n >> k >> m;
    for(int i = 1; i <= m; ++i) {
        cin >> a[i] >> b[i];
    }
    cin >> q;
    for(int i = 1; i <= q; ++i) {
        cin >> Q[i].fi >> Q[i].se;
    }
    if (n <= 300 and m <= 300) {
        return SUB1::sol(), void();
    }
    buildLR();
    if (max(n, max(m, q)) <= 2000 or q == 1) {
        return SUB2::sol(), void();
    }
    bool sub4 = 1;
    FOR(i, 1, max(m, q)) {
        if (i <= m) sub4 &= a[i] < b[i];
        if (i <= q) sub4 &= Q[i].fi < Q[i].se;
    }
    if (sub4) {
        return SUB4::sol(), void();
    }
}


/*     Let the river flows naturally     */

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 11 / 11
• Subtask 4: 0 / 25
• Subtask 5: 0 / 35
• Subtask 6: 0 / 13