Submission #327999

#	Time	Username	Problem	Language	Result	Execution time	Memory
327999		vivaan_gupta	Solar Storm (NOI20_solarstorm)	C++14	62 / 100	2041 ms	76536 KiB

SolarStorm

#include <bits/stdc++.h>
using namespace std;
 
using ll = long long;
using ld = long double;
using db = double; 
using str = string; // yay python!
 
using pi = pair<int,int>;
using pl = pair<ll,ll>;
using pd = pair<db,db>;
 
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<db>; 
using vs = vector<str>;
using vpi = vector<pi>;
using vpl = vector<pl>; 
using vpd = vector<pd>;
 
#define tcT template<class T
// ^ lol this makes everything look weird but I'll try it
tcT> using V = vector<T>; 
tcT, size_t SZ> using AR = array<T,SZ>; 
 
// pairs
#define mp make_pair
#define f first
#define s second
 
// vectors
#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 
 
// 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 trav(a,x) for (auto& a: x)
 
const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5;
const ll INF = 1e18; // not too close to LLONG_MAX
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; // for every grid problem!!
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 
 
// helper funcs
constexpr int pct(int x) { return __builtin_popcount(x); } // # of bits set
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
 
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; }
 
#define tcTU tcT, class U
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(u); } // element that doesn't exist from (multi)set
 
// INPUT
#define tcTUU tcT, class ...U
tcT> void re(complex<T>& c);
tcTU> void re(pair<T,U>& p);
tcT> void re(vector<T>& v);
tcT, size_t SZ> void re(AR<T,SZ>& a);
 
tcT> 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); }
tcTUU> void re(T& t, U&... u) { re(t); re(u...); }
 
tcT> void re(complex<T>& c) { T a,b; re(a,b); c = {a,b}; }
tcTU> void re(pair<T,U>& p) { re(p.f,p.s); }
tcT> void re(vector<T>& x) { trav(a,x) re(a); }
tcT, size_t SZ> void re(AR<T,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
}
tcT> str ts(complex<T> 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; }
tcTU> str ts(pair<T,U> p);
tcT> 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
}
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
}
 
// OUTPUT
tcT> void pr(T x) { cout << ts(x); }
tcTUU> void pr(const T& t, const U&... u) { 
	pr(t); pr(u...); }
void ps() { pr("\n"); } // print w/ spaces
tcTUU> void ps(const T& t, const U&... u) { 
	pr(t); if (sizeof...(u)) pr(" "); ps(u...); }
 
// DEBUG
void DBG() { cerr << "]" << endl; }
tcTUU> void DBG(const T& t, const U&... u) {
	cerr << ts(t); if (sizeof...(u)) cerr << ", ";
	DBG(u...); }
#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
}
#define int ll
const int N = 1e6+5;
int d[N],v[N];
int pref[N];
int val[N];
int le[N],ri[N];
int lef[N],rig[N];
int dist(int i,int j){
	return pref[i] - pref[j];
}
signed main() {
	setIO();	
	int n,s,k;
	re(n,s,k);
	FOR(i,1,n) re(d[i]);
	FOR(i,1,n+1) re(v[i]);
	FOR(i,2,n+1){
		pref[i] = pref[i-1] + d[i-1];
	}
	FOR(i,1,n+1)val[i]=val[i-1]+v[i];
	int ans = -1;
	vl best_pos;
	FOR(i,1,n+1){
		// put a shield at i
		int f = INF;
		int l = 1,r = i;
		while(l <= r){
			int m = (l+r)>>1ll;
			if(dist(i,m) <= k){
				f = min(f, m);
				r = m - 1;
			}
			else l = m+1;
		};
		le[i]=f;
		f = -INF;
		l = i,r = n;
		while(l <= r){
			int m = (l+r)>>1ll;
			if(dist(m,i) <= k){
				f = max(f, m);
				l = m + 1;
			}
			else r = m-1;
		}
		ri[i]=f;
	}
	FOR(i,1,n+1){
		assert(le[i] != INF && ri[i] != -INF);
		// cout << i << " : " << le[i] << " " << ri[i] << endl;

	}
	FOR(i,1,n+1){
		int cur = i;
		int l = cur,r =n;
		int fin = -1;
		while(l <= r){
			int m = (l + r) >> 1ll;
			if(le[m] <= cur){
				fin = max(fin,m);
				l = m+1;
			}
			else r = m-1;
		}
		rig[i] = fin;

	}
	FOR(i,1,n+1){
		int cur = i;
		int l = 1,r = cur;
		int fin = INF;
		while(l <= r){
			int mid =(l+r)>>1ll;
			if(ri[mid] >= cur){
				fin = min(fin,mid);
				r = mid - 1;
			}
			else l = mid + 1;
		}
		lef[i] = fin;
	}


	FOR(i,1,n+1){
		// start putting here
		int tmp = s;
		int cur = i;
		int L = le[i],R=-1;
		vl put;
		while(tmp > 0){
			put.pb(cur);
			cur = ri[cur] + 1;
			R = max(R,cur-1);
			if(cur>n)break;
			cur=rig[cur];
			tmp--;
			if(cur > n) break;
		}	
		R= min(R,n);
		assert(R != -1);
		if((val[R] - val[L-1]) > ans){
			ans = val[R] - val[L-1];
			best_pos = put;
		}
	}
	ROF(i,1,n+1){
		// start putting here
		int tmp = s;
		int cur = i;
		int L = INF,R=ri[i];
		vl put;
		while(tmp > 0){
			put.pb(cur);
			cur = le[cur] - 1;
			L = min(L,cur+1);
			if(cur < 1) break;
			cur=lef[cur];
			tmp--;
			if(cur < 1) break;
		}	
		L= max(L,1ll);
		assert(L != INF);
		if((val[R] - val[L-1]) > ans){
			ans = val[R] - val[L-1];
			best_pos = put;
		}
	}
	
	assert(ans != -1);
	assert(sz(best_pos) <= s);
	sort(all(best_pos));
	cout << sz(best_pos) << endl;
	trav(x,best_pos) cout << x << " ";
	cout << endl;
	
	// you should actually read the stuff at the bottom
}
  
/* stuff you should look for
	* read the probem 3 more times in case of WA :)
	* int overflow, array bounds
	* special cases (n=1?)
	* do smth instead of nothing and stay organized
	* WRITE STUFF DOWN
	* DON'T GET STUCK ON ONE APPROACH
*/

Compilation message (stderr)

SolarStorm.cpp: In function 'void setIn(str)':
SolarStorm.cpp:182:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  182 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
SolarStorm.cpp: In function 'void setOut(str)':
SolarStorm.cpp:183:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  183 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 7 / 7
• Subtask 3: 11 / 11
• Subtask 4: 0 / 8
• Subtask 5: 18 / 18
• Subtask 6: 16 / 16
• Subtask 7: 0 / 30