Submission #477418

#	Time	Username	Problem	Language	Result	Execution time	Memory
477418		kaxzert	Knapsack (NOI18_knapsack)	C++17	12 / 100	126 ms	880 KiB

knapsack

/**
      00  00      11      00  00  111111  00000  111111  000000
      00 00      1111      0000      11   00     11  11  000000
      0000      11  11      00      11    00000  111111    00
      00 00    11111111    0000    11     00     11 11     00
      00  00  11      11  00  00  111111  00000  11  11    00
**/

#include<bits/stdc++.h>

using namespace std;

void setIO(string s) {
    freopen((s+".inp").c_str(),"r",stdin);
    freopen((s+".out").c_str(),"w",stdout);
}

void setIOusaco(string s) {
    freopen((s+".in").c_str(),"r",stdin);
    freopen((s+".out").c_str(),"w",stdout);
}

#define fto(i, a, b) for(int i = a; i <= b; ++i)
#define fdto(i, a, b) for(int i = a; i >= b; --i)
#define bugarr(a, i, j) cout << #a << "{" << i << "..." << j << "}:"; fto(k, i, j-1) cout << a[k] << ", "; cout << a[j] << endl;
#define ll long long
#define db double
#define ldb long double
#define ii pair<int, int>
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define vt vector
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define trav(i, a) for(auto &i : a)
#define sz(a) (int)a.size()
#define fast ios::sync_with_stdio(false); cin.tie(0)

template<typename T, typename V>
bool ckmin(T &a, V b) {return (b < a)? a = b, true : false;}
template<typename T, typename V>
bool ckmax(T &a, V b) {return (b > a)? a = b, true : false;}

void print(int x) {cout << x;}
void print(long long x) {cout << x;}
void print(unsigned x) {cout << x;}
void print(unsigned long long x) {cout << x;}
void print(double x) {cout << fixed << x;}
void print(long double x) {cout << fixed << x;}
void print(char x) {cout << "'" << x << "'";}
void print(string x) {cout << '"' << x << '"';}
void print(bool x) {cout << (x ? "true" : "false");}

template<typename T, typename V>
void print(const pair<T, V> &x) {cout << '{'; print(x.ff); cout << ", "; print(x.ss); cout << '}';}
template<typename T>
void print(const T &x) {int f = 0; cout << '{'; for (auto &i: x) cout << (f++ ? ", " : ""), print(i); cout << "}";}
void _print() {cout << "]" << endl;}
template <typename T, typename... V>
void _print(T t, V... v) {print(t); if (sizeof...(v)) cout << ", "; _print(v...);}

#ifdef TAP
#define bug(x...) cout << "[" << #x << "] = ["; _print(x)
#else
#define bug(x...) 
#endif

int _left = 0, _right;

struct segment_tree {
	vt<ll> nodes, nho;
	segment_tree(){}
	
	void init(int n) {
		nodes.assign((n+1)*4 +3, 0);
		nho.assign((n+1)*4 +3, 0);
	}

	void upd(int root) {
		if (nho[root] == 0) return;
		ll y = nho[root];
		nho[root] = 0;
		nodes[root*2] += y;
		nodes[root*2+1] += y;
		nho[root*2] += y;
		nho[root*2+1] += y; 
	}

	void update(int i, int j, ll v, int root = 1, int left = _left, int right = _right) {
		assert(root <= sz(nodes));
		if (left >= i && right <= j) {
			nodes[root] += v;
			nho[root] += v;
			return;
		}

		if (left > j || right < i) return;

		upd(root);
		int mid = (left+right)/2;
		update(i, j, v, root*2, left, mid);
		update(i, j, v, root*2+1, mid+1, right);
		nodes[root] = max(nodes[root*2], nodes[root*2+1]);
	}

	ll query(int i, int j, int root = 1, int left = _left, int right = _right) {
		assert(root <= sz(nodes));
		if (left >= i && right <= j) return nodes[root];

		if (left > j || right < i) return 0;

		upd(root);
		int mid = (left+right)/2;
		return max(query(i, j, root*2, left, mid), query(i, j, root*2+1, mid+1, right));
	}
};

int main() {

    fast;
    ll s, n;
    cin >> s >> n;
    vt<ll> v(n+1), w(n+1), k(n+1);
   	fto(i, 1, n) {
   		cin >> v[i] >> w[i] >> k[i]; 
   	}

   	vt<vt<ll> > f(2, vt<ll>(s+1));
	fto(i, 1, n) {
   		int li = i&1;
   		fto(j, 1, s) f[li][j] = f[li^1][j];
   		segment_tree tree[w[i]];
   		fto(j, 0, w[i]-1) {
   			_right = (s/(w[i]+j));
   			tree[j].init(s/(w[i]+j));
   		}
   		fto(j, w[i], s) {
   			assert(j%w[i] <= w[i]);
   			ll sth = tree[j%w[i]].query((j/w[i])-1, (j/w[i])-1);
   			tree[j%w[i]].update((j/w[i])-1, (j/w[i])-1, -sth+f[li^1][j-w[i]]);
   			tree[j%w[i]].update(max(0LL, (j/w[i])-k[i]), (j/w[i])-1, v[i]);
   			f[li][j] = max(f[li][j], tree[j%w[i]].query(0, (j/w[i])-1));
   		}
   	}
   	ll ans = 0;
	fto(j, 1, s) ans = max(ans, f[n&1][j]);
	cout << ans << '\n';

    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void setIO(std::string)':
knapsack.cpp:14:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     freopen((s+".inp").c_str(),"r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s+".out").c_str(),"w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp: In function 'void setIOusaco(std::string)':
knapsack.cpp:19:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |     freopen((s+".in").c_str(),"r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:20:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |     freopen((s+".out").c_str(),"w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 0 / 17
• Subtask 3: 0 / 20
• Subtask 4: 0 / 24
• Subtask 5: 0 / 27