Submission #265586

#	Time	Username	Problem	Language	Result	Execution time	Memory
265586		rqi	Cake 3 (JOI19_cake3)	C++14	100 / 100	3328 ms	26216 KiB

cake3

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 

typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 

typedef vector<int> vi; 
typedef vector<bool> vb; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair
#define f first
#define s second
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define sor(x) sort(all(x)) 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

template<class T> bool ckmin(T& a, const T& b) { 
    return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
    return a < b ? a = b, 1 : 0; } 
constexpr int pct(int x) { return __builtin_popcount(x); } 
constexpr int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up
ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down
ll half(ll x) { return fdiv(x,2); }

template<class T, class U> T fstTrue(T lo, T hi, U f) { 
    // note: if (lo+hi)/2 is used instead of half(lo+hi) then this will loop infinitely when lo=hi
    hi ++; assert(lo <= hi); // assuming f is increasing
    while (lo < hi) { // find first index such that f is true 
        T mid = half(lo+hi);
        f(mid) ? hi = mid : lo = mid+1; 
    } 
    return lo;
}
template<class T, class U> T lstTrue(T lo, T hi, U f) {
    lo --; assert(lo <= hi); // assuming f is decreasing
    while (lo < hi) { // find first index such that f is true 
        T mid = half(lo+hi+1);
        f(mid) ? lo = mid : hi = mid-1;
    } 
    return lo;
}
template<class T> void remDup(vector<T>& v) { 
    sort(all(v)); v.erase(unique(all(v)),end(v)); }

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
str ts(bool b) { 
    #ifdef LOCAL
        return b ? "true" : "false"; 
    #else 
        return ts((int)b);
    #endif
}
template<class A> str ts(complex<A> c) { 
    stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) {
    str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
    res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; F0R(i,SZ) res += char('0'+b[i]);
    return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
    #ifdef LOCAL
        bool fst = 1; str res = "{";
        for (const auto& x: v) {
            if (!fst) res += ", ";
            fst = 0; res += ts(x);
        }
        res += "}"; return res;
    #else
        bool fst = 1; str res = "";
        for (const auto& x: v) {
            if (!fst) res += " ";
            fst = 0; res += ts(x);
        }
        return res;

    #endif
}
template<class A, class B> str ts(pair<A,B> p) {
    #ifdef LOCAL
        return "("+ts(p.f)+", "+ts(p.s)+")"; 
    #else
        return ts(p.f)+" "+ts(p.s);
    #endif
}

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
    pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
    pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << ts(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL, chk -> fake assert
    #define dbg(...) cerr << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
    #define chk(...) if (!(__VA_ARGS__)) cerr << "Line(" << __LINE__ << ") -> function(" \
         << __FUNCTION__  << ") -> CHK FAILED: (" << #__VA_ARGS__ << ")" << "\n", exit(0);
#else
    #define dbg(...) 0
    #define chk(...) 0
#endif

// FILE I/O
void setIn(str s) { freopen(s.c_str(),"r",stdin); }
void setOut(str s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { cin.tie(0)->sync_with_stdio(0); }
void setIO(str s = "") {
    unsyncIO();
    // cin.exceptions(cin.failbit); 
    // throws exception when do smth illegal
    // ex. try to read letter into int
    if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}

typedef pair<ll, int> T;
/**
 * Description: 1D range update and query, $SZ=2^p$.
 * Source: USACO Counting Haybales
 * Verification: SPOJ Horrible
 */
 
struct LazySeg { 
    int SZ;
    vector<T> sum;
    vl vals;
    vi to;
 
    LazySeg(vl ats) { 
        SZ = 1;
        while(SZ-1 < sz(ats)-1){
            SZ*=2;
        }
 
        to = vi(sz(ats), 0);
        vector<pair<ll, int>> mto;
        for(int i = 0; i < sz(ats); i++){
            mto.pb(mp(ats[i], i));
        }
        sort(all(mto));
 
        for(int i = 0; i < sz(mto); i++){
            int ind = mto[i].s;
            to[ind] = i;
            vals.pb(mto[i].f);
        }
 
        sum = vector<T>(2*SZ, mp(ll(0), 0));
        for(int i = 0; i < sz(ats); i++){
            int ind = to[i];
            sum[SZ+ind] = mp(0, 0);
        }
    }
 
    T comb(T a, T b){
        return mp(a.f+b.f, a.s+b.s);
    }
    // recalc values for current node
    void pull(int ind) { sum[ind] = comb(sum[2*ind], sum[2*ind+1]); }
    void build() { ROF(i,1,SZ) pull(i); }
    void upd(int i, int on, int ind, int L, int R) {
        assert(L <= i && i <= R);
 
        if (L == i && R == i) { 
            if(sum[ind].s != on){
                sum[ind].f^=vals[i];
                sum[ind].s^=1;
            }
            assert(sum[ind].s == on); 
            return; 
        }
 
        int M = (L+R)/2; 
        if(i <= M) upd(i, on, 2*ind,L,M); 
        else upd(i, on, 2*ind+1,M+1,R); 
        pull(ind);
    }
 
    void upd(int ind, int on){ //turning on or off
        upd(to[ind], on, 1, 0, SZ-1);
    }
 
    ll topk(int k){ //query sum of the top k
        if(sum[1].s == k) return sum[1].f;
        if(sum[1].s < k) return -INF;
        T ans = mp(ll(0), 0);
        int ind = 1;
        while(2*ind+1 < 2*SZ){
            if(comb(ans, sum[2*ind+1]).s <= k){
                ans = comb(ans, sum[2*ind+1]);
                ind = 2*ind;
            }
            else{
                ind = 2*ind+1;
            }
        }
        return ans.f;
    }
};

const int mx = 200005;
pl CV[mx];
int N, M;
ll ans = -INF;
LazySeg lseg({});
//int num = 0;

void solve(int l, int r, int L, int R){ //[1, l-1] = 0, [l, L-1] = 1, [L, R] = 0, [R+1, N] = 0
    if(l > r) return;
    //num+=(r-l)+(R-L);
    // dbg(l, r, L, R);
    // for(int i = 1; i <= N; i++){
    //     dbg(i, lseg.sum[i+lseg.SZ], lseg.vals[i]);
    // }
    // if(l == 4 && r == 6 && L == 7 && R == 8){
    //     for(int i = 1; i <= N; i++){
    //         dbg(i, lseg.sum[i+lseg.SZ], lseg.vals[i]);
    //     }
    // }
    if(R-l+1 < M) return;
    ckmax(L, l);
    //assert(L >= l);
    int m = (l+r)/2;
    int ind = -1;
    ll cans = -INF;
    for(int i = l; i <= m; i++){
        lseg.upd(i, 0);
        //num++;
    }
    for(int i = max(m+1, L); i <= R; i++){
        ll pans = lseg.topk(M-2)+CV[i].s+CV[m].s-2*(CV[i].f-CV[m].f);
        if(pans > cans){
            cans = pans;
            ind = i;
        }
        lseg.upd(i, 1);
        //num+=2;
    }
    //dbg(l, r, L, R, m, ind);
    ckmax(ans, cans);
    // for(int i = l; i <= min(L-1, m); i++){
    //     lseg.upd(i, 1);
    //     num++;
    // }
    // for(int i = max(m+1, L); i <= R; i++){
    //     lseg.upd(i, 0);
    //     num++;
    // }
    
    // for(int i = l; i <= m; i++){
    //     lseg.upd(i, 0);
    //     num++;
    // }
    // for(int i = max(m+1, L); i <= ind-1; i++){
    //     lseg.upd(i, 1);
    //     num++;
    // }
    // for(int i = l; i <= m; i++){
    //     lseg.upd(i, 0);
    //     //num++;
    // }
    // for(int i = L; i <= ind-1; i++){
    //     lseg.upd(i, 1);
    //     //num++;
    // }

    for(int i = ind; i <= R; i++){
        lseg.upd(i, 0);
    }
    for(int i = l; i <= min(L-1, m); i++){
        lseg.upd(i, 0);
    }
    solve(m+1, r, ind, R);
    for(int i = max(m+1, L); i <= ind-1; i++){
        lseg.upd(i, 0);
        //num++;
    }
    for(int i = l; i <= min(L-1, m); i++){
        lseg.upd(i, 1);
        //num++;
    }

    solve(l, m-1, L, ind); 

    // dbg(l, r, L, R);
    // for(int i = 1; i <= N; i++){
    //     dbg(i, lseg.sum[i+lseg.SZ], lseg.vals[i]);
    // }
}

int main() {
    setIO();
    
    cin >> N >> M;
    for(int i = 1; i <= N; i++){
        cin >> CV[i].s >> CV[i].f;
    }
    sort(CV+1, CV+1+N);
    vl vals;
    vals.pb(0);
    for(int i = 1; i <= N; i++){
        vals.pb(CV[i].s);
    }
    lseg = LazySeg({vals});
    solve(1, N-M+1, 1, N);
    ps(ans);
    //dbg(num);
    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
*/

Compilation message (stderr)

cake3.cpp: In function 'void setIn(str)':
cake3.cpp:168:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  168 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
cake3.cpp: In function 'void setOut(str)':
cake3.cpp:169:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  169 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 76 / 76