Submission #759097

# Submission time Handle Problem Language Result Execution time Memory
759097 2023-06-15T18:41:38 Z NK_ Divide and conquer (IZhO14_divide) C++17
0 / 100
1 ms 320 KB
#include <bits/stdc++.h>

using namespace std;

/////////////////////// MACROS ////////////////////////////////////////////
using ll = long long;
using ld = long double;
using db = double;
using str = string;

using pi = pair<int,int>;
using pl = pair<ll,ll>;

using vi = vector<int>;
using vl = vector<ll>;
using vs = vector<str>;
using vc = vector<char>;
using vpi = vector<pi>;
using vpl = vector<pl>;

#define tcT template<class T
#define tcTU tcT, class U
tcT> using V = vector<T>;
tcT, size_t SZ> using AR = array<T,SZ>;
tcTU> using PR = pair<T,U>;
tcTU> using umap = unordered_map<T, U>;
tcT> using uset = unordered_set<T>;
tcT> using mset = multiset<T>;

#define mp make_pair
#define f first
#define s second

#define sz(x) int((x).size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define ppb pop_back()
#define ppf pop_front()
#define pb push_back
#define eb emplace_back
#define pf push_front

#define lb lower_bound
#define ub upper_bound

// LOOPS
#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 rep(a) F0R(_, a)
#define each(a,x) for (auto& a: x)

/////////////////////// IMPORANT VARS /////////////////////////////////////

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5;
const ll INFL = ll(3e18)+10;
const int INF = int(1e9)+10;
const ld PI = acos((ld)-1);
const int dx[4] = {1,0,-1,0}, dy[4] = {0,1,0,-1};
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;
tcT> using pql = priority_queue<T,vector<T>,less<T>>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define nl '\n'

constexpr int pct(int x) { return __builtin_popcount(x); } // # of bits set
constexpr int bits(int x) { 
	return x == 0 ? 0 : 31-__builtin_clz(x); }
constexpr int p2(int x) { return 1<<x; }
constexpr int msk2(int x) { return p2(x)-1; }
 
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
 
tcT> bool ckmin(T& a, const T& b) {
	return b < a ? a = b, 1 : 0; } // set a = min(a,b)
tcT> bool ckmax(T& a, const T& b) {
	return a < b ? a = b, 1 : 0; }
 
tcTU> T fstTrue(T lo, T hi, U f) {
	hi ++; assert(lo <= hi); // assuming f is increasing
	while (lo < hi) { // find first index such that f is true 
		T mid = lo+(hi-lo)/2;
		f(mid) ? hi = mid : lo = mid+1; 
	} 
	return lo;
}
tcTU> 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 = lo+(hi-lo+1)/2;
		f(mid) ? lo = mid : hi = mid-1;
	} 
	return lo;
}
tcT> void remDup(vector<T>& v) { // sort and remove duplicates
	sort(all(v)); v.erase(unique(all(v)),end(v)); }
tcTU> void erase(T& t, const U& u) { // don't erase
	auto it = t.find(u); assert(it != end(t));
	t.erase(it); } // element that doesn't exist from (multi)set


// #include <ext/pb_ds/assoc_container.hpp>
// using namespace __gnu_pbds;

// tcT> using iset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>; 
// #define ook order_of_key
// #define fbo find_by_order

// struct chash { 
// 	const uint64_t C = ll(2e18*PI)+71;
// 	const int RANDOM = rng();
// 	ll operator()(ll x) const {
// 		return __builtin_bswap64((x^RANDOM)*C); }
// };
// template<class K,class V> using um = unordered_map<K,V,chash>;
// template<class K,class V> using ht = gp_hash_table<K,V,chash>;
// template<class K,class V> V get(ht<K,V>& u, K x) {
// 	auto it = u.find(x); return it == end(u) ? 0 : it->s; }

/////////////////////// OUPUT /////////////////////////////////////////////
#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
}
tcTU> str ts(pair<T,U> p) {
	#ifdef LOCAL
		return "("+ts(p.f)+", "+ts(p.s)+")";
	#else
		return ts(p.f)+" "+ts(p.s);
	#endif
}

tcTU> str ts(V<pair<T, U>> v) {
	#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
}

tcT> str ts(T v) {
	#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
}

///////////////////////// DEBUG ///////////////////////////////////////////
#define tcTUU tcT, class ...U
void DBG() { cerr << "]" << "\e[0m" << endl; }
tcTUU> void DBG(const T& t, const U&... u) {
	cerr << ts(t); if (sizeof...(u)) cerr << ", ";
	DBG(u...); }
#ifdef LOCAL
	#define dbg(...) cerr << "\e[1m" << "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 unsyncIO() { cin.tie(0)->sync_with_stdio(0); }
void setPrec() { cout << fixed << setprecision(15); }
void setIn(str s) { freopen(s.c_str(),"r",stdin); }
void setOut(str s) { freopen(s.c_str(),"w",stdout); }
void setIO(str s = "") {
	unsyncIO(); setPrec();
	#ifndef LOCAL	
		if (sz(s)) setIn(s+".in"), setOut(s+".out"); // for USACO
	#endif
}

///////////////////////// TEMPLATE ABOVE //////////////////////////////////

// REMEMBER
// - Don't Focus On Only One Approach
// - Read And Understand Problem Fully
// - Think Of Edges Cases
// - Implement Carefully
// - Always Check For Overflows
// - Reset Global Variables
// - Look At The Bigger Picture
// - Don't Get Discouraged, You Can Pull It Back

tcT> struct Seg { 
	const T ID = -INFL; T comb(T a, T b) { return max(a, b); }
	V<T> seg, lazy; int n;
	void init(int _n) { n = 1; while(n < _n) n *= 2;  seg.assign(2*n, ID), lazy.assign(2*n, 0); }
	void push(int x, int L, int R) { /// modify values for current node
		seg[x] += lazy[x]; // dependent on operation
		if (L != R) F0R(i,2) lazy[2*x+i] += lazy[x]; /// prop to children
		lazy[x] = 0; 
	} // recalc values for current node
	void pull(int x) { seg[x] = comb(seg[2*x],seg[2*x+1]); }
	void build() { ROF(i,1,n) pull(i); }
	void upd(int lo, int hi, T v, int x, int L, int R) {
		push(x,L,R); if (hi < L || R < lo) return;
		if (lo <= L && R <= hi) { 
			lazy[x] = v; push(x,L,R); return; }
		int M = (L+R)/2; upd(lo, hi, v, 2*x, L, M); 
		upd(lo, hi, v, 2*x+1, M+1, R); pull(x);
	}
	T query(int lo, int hi, int x, int L, int R) {
		push(x,L,R); if (lo > R || L > hi) return ID;
		if (lo <= L && R <= hi) return seg[x];
		int M = (L+R)/2; 
		return comb(query(lo,hi,2*x,L,M),query(lo,hi,2*x+1,M+1,R));
	}

	int last_at_least(ll val, int ind, int l, int r) { // if seg stores max across range
		dbg(l, r, seg[ind]);
		if (val > seg[ind]) return -1;
		if (l == r) return l;
		int m = (l+r)/2;
		int res = last_at_least(val,2*ind+1,m+1,r); if (res != -1) return res;
		return last_at_least(val,2*ind,l,m);
	}
	int get_last(int v) { return last_at_least(v, 1, 0, n-1); }
	
	void set(int p, T val) { // set val at position p
		seg[p += n] = val; for (p /= 2; p; p /= 2) pull(p); }
	void upd(int lo, int hi, T v) { upd(lo, hi, v, 1, 0, n-1); }
	T query(int lo, int hi) { return query(lo, hi, 1, 0, n-1); }
};

void solve() {
	int N; cin >> N;

	vl P; int prv = -1;
	V<AR<int, 3>> A(N);

	vl G = {0}; auto qry = [&](int l, int r) {
		return G[r + 1] - G[l];
	};	

	F0R(i, N) {
		cin >> A[i][0] >> A[i][1] >> A[i][2];
		G.pb(G.bk + A[i][1]);

		if (prv == -1) P.pb(A[i][2]);
		else P.pb(P.bk - (A[i][0] - prv) + A[i][2]);
		prv = A[i][0];
	}
	dbg(P);

	Seg<ll> st; st.init(N);
	F0R(i, N) st.set(i, P[i]);
	st.build();

	ll ans = -INFL;
	F0R(l, N) {
		int r = st.get_last(0);
		dbg(r);
		ckmax(ans, qry(l, r));

		st.upd(l, N - 1, -A[l][2]);
		if (l + 1 < N) st.upd(l + 1, N - 1, A[l+1][0] - A[l][0]);
	}

	cout << ans << nl;
}

int main() {
	setIO(); 

	int TT = 1;
	// cin >> TT;

	rep(TT) solve();
	
	exit(0-0);
}

Compilation message

divide.cpp: In function 'void solve()':
divide.cpp:194:19: warning: statement has no effect [-Wunused-value]
  194 |  #define dbg(...) 0
      |                   ^
divide.cpp:281:2: note: in expansion of macro 'dbg'
  281 |  dbg(P);
      |  ^~~
divide.cpp:194:19: warning: statement has no effect [-Wunused-value]
  194 |  #define dbg(...) 0
      |                   ^
divide.cpp:290:3: note: in expansion of macro 'dbg'
  290 |   dbg(r);
      |   ^~~
divide.cpp: In instantiation of 'int Seg<T>::last_at_least(ll, int, int, int) [with T = long long int; ll = long long int]':
divide.cpp:255:31:   required from 'int Seg<T>::get_last(int) [with T = long long int]'
divide.cpp:289:24:   required from here
divide.cpp:194:19: warning: statement has no effect [-Wunused-value]
  194 |  #define dbg(...) 0
      |                   ^
divide.cpp:248:3: note: in expansion of macro 'dbg'
  248 |   dbg(l, r, seg[ind]);
      |   ^~~
divide.cpp: In function 'void setIn(str)':
divide.cpp:201:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  201 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
divide.cpp: In function 'void setOut(str)':
divide.cpp:202:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  202 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 1 ms 320 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 1 ms 320 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 1 ms 320 KB Output isn't correct
3 Halted 0 ms 0 KB -