Submission #242934

#	Time	Username	Problem	Language	Result	Execution time	Memory
242934		rqi	Global Warming (CEOI18_glo)	C++14	100 / 100	152 ms	11816 KiB

glo

#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<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 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; } 
int pct(int x) { return __builtin_popcount(x); } 
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 
int fstTrue(function<bool(int)> f, int lo, int hi) {
    hi ++; assert(lo <= hi); // assuming f is increasing
    while (lo < hi) { // find first index such that f is true 
        int mid = (lo+hi)/2; 
        f(mid) ? hi = mid : lo = mid+1; 
    } 
    return lo;
}

// 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(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
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()
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }

// 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
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string 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
}




/**
 * Description: 1D point update, range query where \texttt{comb} is
     * any associative operation. If $N=2^p$ then \texttt{seg[1]==query(0,N-1)}.
 * Time: O(\log N)
 * Source: 
    * http://codeforces.com/blog/entry/18051
    * KACTL
 * Verification: SPOJ Fenwick
 */

template<class T> struct Seg { // comb(ID,b) = b
    const T ID = 0; T comb(T a, T b) { return max(a, b); } 
    int n; vector<T> seg;
    void init(int _n) { n = _n; seg.assign(2*n,ID); }
    void pull(int p) { seg[p] = comb(seg[2*p],seg[2*p+1]); }
    void upd(int p, T val) { // set val at position p
        seg[p += n] = val; for (p /= 2; p; p /= 2) pull(p); }
    T query(int l, int r) {    // sum on interval [l, r]
        T ra = ID, rb = ID; 
        for (l += n, r += n+1; l < r; l /= 2, r /= 2) {
            if (l&1) ra = comb(ra,seg[l++]);
            if (r&1) rb = comb(seg[--r],rb);
        }
        return comb(ra,rb);
    }
};

const int mx = 200005;
int n, x;
int t[mx];
Seg<int> mseg;

vi getvi(){
    vi rval;
    vi lens;
    lens.pb(0);
    for(int i = 0; i < n; i++){
        //dbg(i, t[i]);
        int lo = 0;
        int hi = sz(lens)-1;
        while(lo < hi){
            int mid = (lo+hi)/2+1;
            if(lens[mid] < t[i]){
                lo = mid;
            }
            else hi = mid-1;
        }
        rval.pb(lo+1);
        if(lo == sz(lens)-1){
            lens.pb(t[i]);
        }
        else{
            lens[lo+1] = t[i];
        }
    }
    return rval;
}

int main() {
    setIO();
    cin >> n >> x;
    for(int i = 0; i < n; i++){
        cin >> t[i];
    }

    vi a = getvi();
    vpi queries;
    for(int i = 0; i < n; i++){
        queries.pb(mp(t[i], i));
    }
    sort(queries.rbegin(), queries.rend());

    for(int i = 0; i < n/2; i++){
        swap(t[i], t[n-1-i]);
    }
    for(int i = 0; i < n; i++){
        t[i] = -t[i];
    }

    vi b = getvi();
    reverse(all(b));
    for(int i = 0; i < n/2; i++){
        swap(t[i], t[n-1-i]);
    }
    for(int i = 0; i < n; i++){
        t[i] = -t[i];
    }

    //dbg(a, b);

    vpi g;

    for(int i = 0; i < n; i++){
        g.pb(mp(t[i], i));
    }

    sort(g.rbegin(), g.rend());

    // for(int i = 0; i < n; i++){
    //     dbg(i, t[i]);
    // }

    //dbg(queries, g);

    mseg.init(n+5);
    int gind = 0;
    int ans = 0;
    for(int i = 0; i < n; i++){
        while(gind < sz(g)){
            if(queries[i].f >= g[gind].f+x){
                break;
            }
            int ind = g[gind].s;
            mseg.upd(ind, b[ind]);
            gind++;
        }
        int ind = queries[i].s;
        ckmax(ans, a[ind]+mseg.query(ind+1, n+1));
    }
    ps(ans);
    // 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)

glo.cpp: In function 'void setIn(std::__cxx11::string)':
glo.cpp:128:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
glo.cpp: In function 'void setOut(std::__cxx11::string)':
glo.cpp:129:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25