Submission #117114

#	Time	Username	Problem	Language	Result	Execution time	Memory
117114		eriksuenderhauf	Salesman (IOI09_salesman)	C++11	100 / 100	611 ms	17388 KiB

salesman

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
#define mem(a,v) memset((a), (v), sizeof (a))
#define enl printf("\n")
#define case(t) printf("Case #%d: ", (t))
#define ni(n) scanf("%d", &(n))
#define nl(n) scanf("%I64d", &(n))
#define nai(a, n) for (int i = 0; i < (n); i++) ni(a[i])
#define nal(a, n) for (int i = 0; i < (n); i++) nl(a[i])
#define pri(n) printf("%d\n", (n))
#define prl(n) printf("%I64d\n", (n))
#define pii pair<int, int>
#define pil pair<int, long long>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vil vector<pil>
#define vll vector<pll>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef cc_hash_table<int,int,hash<int>> ht;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
const double pi = acos(-1);
const int MOD = 1e9 + 7;
const int INF = 2e9 + 7;
const int MAXN = 524289;
const double eps = 1e-9;
int dp[MAXN], BIT1[MAXN], BIT2[MAXN];

void upd1(int ind, int v) {
	ind = MAXN - ind - 1;
	while (ind < MAXN) {
		BIT1[ind] = max(BIT1[ind], v);
		ind += ind & -ind;
	}
}

void upd2(int ind, int v) {
	ind++;
	while (ind < MAXN) {
		BIT2[ind] = max(BIT2[ind], v);
		ind += ind & -ind;
	}
}

int qry1(int ind) {
	ind = MAXN - ind - 1;
	int ret = -INF;
	while (ind > 0) {
		ret = max(ret, BIT1[ind]);
		ind -= ind & -ind;
	}
	return ret;
}

int qry2(int ind) {
	ind++;
	int ret = -INF;
	while (ind > 0) {
		ret = max(ret, BIT2[ind]);
		ind -= ind & -ind;
	}
	return ret;
}

int ind[MAXN], rev[MAXN];
pair<int,pii> a[MAXN];

int main() {
	int n, u, d, s;
	scanf("%d %d %d %d", &n, &u, &d, &s);
	a[0] = mp(-1, mp(s, 0));
	for (int i = 1; i <= n; i++) {
		scanf("%d %d %d", &a[i].fi, &a[i].se.fi, &a[i].se.se);
		ind[i] = i;
	}
	sort(ind, ind + n+1, [](int l, int r) {
		return a[l].se.fi < a[r].se.fi;
	});
	for (int i = 0; i <= n; i++) {
		dp[i] = -INF;
		rev[ind[i]] = i;
	}
	sort(ind, ind + n+1, [](int l, int r) {
		if (a[l].fi == a[r].fi)
			return a[l].se.fi < a[r].se.fi;
		return a[l].fi < a[r].fi;
	});
	dp[0] = 0;
	dp[n+1] = 0;
	for (int i = 0; i < MAXN; i++)
		BIT1[i] = BIT2[i] = -INF;
	upd1(rev[0], dp[0] - u * s);
	upd2(rev[0], dp[0] + d * s);
	for (int i = 1; i <= n; i++) {
		int j = i;
		for (; j <= n && a[ind[j]].fi == a[ind[i]].fi; j++) {
			int cur = ind[j];
			int v1 = qry1(rev[cur]); // upwards
			if (v1 != -INF) dp[j] = max(dp[j], a[cur].se.se + v1 + u * a[cur].se.fi);
			int v2 = qry2(rev[cur]); // downwards
			if (v2 != -INF) dp[j] = max(dp[j], a[cur].se.se + v2 - d * a[cur].se.fi);
		}
		int hi = j - 1;
		vi pre, suf;
		// upwards
		int tmp = -INF;
		int sm = 0;
		for (j = i; j <= hi; j++) {
			int cur = ind[j];
			sm += a[cur].se.se;
			if (tmp == -INF)
				pre.pb(-INF);
			else
				pre.pb(tmp + sm - d * a[cur].se.fi);
			if (dp[j] != -INF)
				tmp = max(tmp, dp[j] + d * a[cur].se.fi - sm);
		}
		tmp = -INF;
		sm = 0;
		// downwards
		for (j = hi; j >= i; j--) {
			int cur = ind[j];
			sm += a[cur].se.se;
			if (tmp == -INF)
				suf.pb(-INF);
			else
				suf.pb(tmp + sm + u * a[cur].se.fi);
			if (dp[j] != -INF)
				tmp = max(tmp, dp[j] - u * a[cur].se.fi - sm);
		}
		reverse(suf.begin(), suf.end());
		for (j = i; j <= hi; j++) {
			int cur = ind[j];
			//cerr << dp[j] << " " << pre[j-i] << " " << suf[j-i] << "\n";
			dp[j] = max(dp[j], max(pre[j-i], suf[j-i]));
			if (dp[j] != -INF) {
				upd1(rev[cur], dp[j] - u * a[cur].se.fi);
				upd2(rev[cur], dp[j] + d * a[cur].se.fi);
			}
		}
		i = hi;
	}
	int v1 = qry1(rev[0]); // upwards
	if (v1 != -INF)
		dp[n+1] = max(dp[n+1], v1 + u * s);
	int v2 = qry2(rev[0]); // downwards
	if (v2 != -INF)
		dp[n+1] = max(dp[n+1], v2 - d * s);
	printf("%d\n", dp[n+1]);
	return 0;
}

Compilation message (stderr)

salesman.cpp: In function 'int main()':
salesman.cpp:80:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d %d", &n, &u, &d, &s);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
salesman.cpp:83:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d", &a[i].fi, &a[i].se.fi, &a[i].se.se);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100