Submission #831247

#	Time	Username	Problem	Language	Result	Execution time	Memory
831247		79brue	Meetings (IOI18_meetings)	C++17	100 / 100	5086 ms	742440 KiB

meetings

#include "meetings.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int MX = 750002;

int n, q;
ll arr[MX];
int ql[MX], qr[MX];
ll ans[MX];

void solve();

vector<ll> minimum_costs(vector<int> H, vector<int> L, vector<int> R){
    n = (int)H.size();
    for(int i=1; i<=n; i++) arr[i] = H[i-1];
    q = (int)L.size();
    for(int i=1; i<=q; i++) ql[i] = L[i-1]+1, qr[i] = R[i-1]+1, ans[i] = LLONG_MAX;

    solve();

    vector<ll> ret;
    for(int i=1; i<=q; i++) ret.push_back(ans[i]);
    return ret;
}

void makeCartesianTree();
void reformQuery();
void calculateAnswer();

int mult = 1;
void solve(){
    makeCartesianTree();
    reformQuery();
    calculateAnswer();

    reverse(arr+1, arr+n+1);
    for(int i=1; i<=q; i++) ql[i] = n+1-ql[i], qr[i] = n+1-qr[i], swap(ql[i], qr[i]);
    mult = -1;

    makeCartesianTree();
    reformQuery();
    calculateAnswer();
}

struct segTree{
    pair<int, int> tree[1<<21];

    void init(int i, int l, int r, ll *A){
        if(l==r){
            tree[i] = make_pair(A[l], l * mult);
            return;
        }
        int m = (l+r)>>1;
        init(i*2, l, m, A);
        init(i*2+1, m+1, r, A);
        tree[i] = max(tree[i*2], tree[i*2+1]);
    }

    pair<int, int> query(int i, int l, int r, int s, int e){
        if(r<s || e<l) return make_pair(0, 0);
        if(s<=l && r<=e) return tree[i];
        int m = (l+r)>>1;
        return max(query(i*2, l, m, s, e), query(i*2+1, m+1, r, s, e));
    }
} tree;

int par[MX], lc[MX], rc[MX];
int intvL[MX], intvR[MX], root;
int thisL[MX];

int dnc(int l, int r, int p=0){
    if(l>r) return 0;
    int x = mult * tree.query(1, 1, n, l, r).second;
    par[x] = p;
    intvL[x] = l, intvR[x] = r;
    lc[x] = dnc(l, x-1);
    rc[x] = dnc(x+1, r);
    thisL[intvL[x]] = x;
    // printf("thisL[%d] = %d\n", intvL[x], x);
    return x;
}

void makeCartesianTree(){
    for(int i=1; i<=n; i++){
        par[i] = lc[i] = rc[i] = thisL[i] = 0;
    }
    tree.init(1, 1, n, arr);
    root = dnc(1, n);
}

vector<int> vec[MX];

void reformQuery(){
    for(int i=1; i<=n; i++) vec[i].clear();
    for(int i=1; i<=q; i++){
        if(ql[i] == qr[i]){
            ans[i] = arr[ql[i]];
            continue;
        }
        int l = ql[i], r = qr[i], x = mult * tree.query(1, 1, n, l, r).second;
        if(x==qr[i]) ans[i] = min(ans[i], arr[x] * (r-l+1));
        else vec[thisL[x+1]].push_back(i);

        //printf("Pushed %d to %d (x %d)\n", i, thisL[x+1], x);
    }
}

ll lazy[MX], rEnd[MX];
ll setA[MX], setB[MX];
deque<ll> dq[MX];

ll backVal(int x){
    int t = dq[x].back();
    // printf("backVal[%d] = %lld (t=%d)\n", x, setA[t] * rEnd[t] + setB[t] + lazy[x], t);
    return setA[t] * rEnd[t] + setB[t] + lazy[x];
}

ll calc(int x, ll v){
    if(!(!dq[x].empty() && dq[x][0] <= v)){
        printf("calc x: %d, v: %lld\n", x, v);
        printf("dq[%d]: ", x); for(int p: dq[x]) printf("%d-%d ", p, rEnd[p]); puts("");
        exit(1);
    }
    int p = *prev(upper_bound(dq[x].begin(), dq[x].end(), v));
    return setA[p] * v + setB[p] + lazy[x];
}

void render(int x, ll a, ll b){
    if(dq[x].empty() || setA[dq[x].front()] * dq[x].front() + setB[dq[x].front()] + lazy[x] <= a*dq[x].front()+b)
        return;
    ll L = dq[x].front(), R = L-1;
    while(!dq[x].empty()){
        int f = dq[x].front();
        if(setA[f] * f + setB[f] + lazy[x] < a * f + b) break;
        if(setA[f] * rEnd[f] + setB[f] + lazy[x] >= a * rEnd[f] + b){
            R = rEnd[f];
            dq[x].pop_front();
            continue;
        }

        while(setA[f] * (R+1) + setB[f] + lazy[x] > a * (R+1) + b) R++;
        dq[x].front() = R+1;
        setA[R+1] = setA[f], setB[R+1] = setB[f], rEnd[R+1] = rEnd[f];
        if(R+1 != f) setA[f] = setB[f] = rEnd[f] = 0;
        break;

        ll ad = a - setA[f], bd = setB[f] + lazy[x] - b;
        ll newL = ceil((long double)(bd) / (long double)(ad));
        dq[x].front() = newL;
        setA[newL] = setA[f], setB[newL] = setB[f], rEnd[newL] = rEnd[f];
        if(newL != f) setA[f] = setB[f] = rEnd[f] = 0;
        break;
    }
    //printf("After render, [%d - %d] is formed\n", L, R);
    if(L<=R){
        dq[x].push_front(L);
        rEnd[L] = R;
        setA[L] = a, setB[L] = b - lazy[x];

        //printf("dq[%d]: ", x); for(int p: dq[x]) printf("%d ", p); puts("");
    }
}

void merge(ll a, ll b){
    if((int)dq[a].size() > dq[b].size()){
        for(int x: dq[b]) dq[a].push_back(x), setB[x] += lazy[b] - lazy[a];
    }
    else{
        for(int i=(int)dq[a].size()-1; i>=0; i--){
            dq[b].push_front(dq[a][i]);
            setB[dq[b].front()] += lazy[a] - lazy[b];
        }
        dq[a].swap(dq[b]);
        lazy[a] = lazy[b];
    }
    dq[b].clear();
    dq[b].shrink_to_fit();
}

void dnc(int x){
    int L = intvL[x], R = intvR[x];
    // printf("dnc %d %d %d\n", x, L, R);

    /// [L, x]
    if(lc[x]){
        dnc(lc[x]);
        lazy[x] = lazy[lc[x]], dq[x].swap(dq[lc[x]]);
        setA[x] = 0, setB[x] = backVal(x) + arr[x] - lazy[x];
        dq[x].push_back(x);
    }
    else{
        dq[x].push_back(x);
        rEnd[x] = x;
        setA[x] = 0, setB[x] = arr[x] - lazy[x];
    }

    if(rc[x]){
        dnc(rc[x]);
        /// DP[rc[x]] 앞부분을 다듬는다
        ll v = backVal(x), vAll = arr[x] * (x-L+1);
        // printf("Added %lld to %d\n", vAll, rc[x]);
        lazy[rc[x]] += vAll;
        render(rc[x], arr[x], v-arr[x]*x);
        merge(x, rc[x]);
    }

    for(int idx: vec[x]){
        ans[idx] = min(ans[idx], calc(x, qr[idx]) + arr[intvL[x]-1] * (intvL[x] - ql[idx]));
        //printf("Checking %d: maybe %lld + %lld = %lld\n", idx, calc(x, qr[idx]), arr[intvL[x]-1]*(intvL[x]-ql[idx]),
            //calc(x, qr[idx]) + arr[intvL[x]-1] * (intvL[x] - ql[idx]));
    }

    //printf("Deque of %d\n", x);
    //for(int p: dq[x]) printf("[%d-%d] %lldx + %lld, \t", p, rEnd[p], setA[p], setB[p]+lazy[x]); puts("");
}

void calculateAnswer(){
    for(int i=1; i<=n; i++){
        lazy[i] = 0, rEnd[i] = i, setA[i] = setB[i] = 0;
        dq[i].clear();
    }
    dnc(root);
}

Compilation message (stderr)

meetings.cpp: In function 'll calc(int, ll)':
meetings.cpp:124:62: warning: format '%d' expects argument of type 'int', but argument 3 has type 'll' {aka 'long long int'} [-Wformat=]
  124 |         printf("dq[%d]: ", x); for(int p: dq[x]) printf("%d-%d ", p, rEnd[p]); puts("");
      |                                                             ~^       ~~~~~~~
      |                                                              |             |
      |                                                              int           ll {aka long long int}
      |                                                             %lld
meetings.cpp: In function 'void merge(ll, ll)':
meetings.cpp:168:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  168 |     if((int)dq[a].size() > dq[b].size()){
      |        ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
meetings.cpp: In function 'void dnc(int)':
meetings.cpp:184:23: warning: unused variable 'R' [-Wunused-variable]
  184 |     int L = intvL[x], R = intvR[x];
      |                       ^

• Subtask 1: 4 / 4
• Subtask 2: 15 / 15
• Subtask 3: 17 / 17
• Subtask 4: 24 / 24
• Subtask 5: 40 / 40