Submission #391802

#	Time	Username	Problem	Language	Result	Execution time	Memory
391802		maomao90	Feast (NOI19_feast)	C++14	100 / 100	180 ms	16304 KiB

feast

#include <bits/stdc++.h>
using namespace std;

#define mnto(x, y) x = min(x, (__typeof__(x)) y)
#define mxto(x, y) x = max(x, (__typeof__(x)) y)
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
#define MP make_pair
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define MT make_tuple
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb emplace_back
typedef vector<int> vi;
typedef vector<ii> vii;

#define INF 1000000005
#define LINF 100000000000000005
#define MOD 1000000007
#define MAXN 300005

int n, k;
int a[MAXN];
pll dp[MAXN], g[MAXN];
ll pre[MAXN];
pll check(ll x) {
	// dp[i] = max(g[j] - pre[j]) + pre[i]
	pll curMax = MP(0, 0);
	REP (i, 1, n + 1) {
		dp[i] = MP(curMax.FI + pre[i] - x, curMax.SE + 1);
		g[i] = max(g[i - 1], dp[i]);
		if (g[i].FI - pre[i] > curMax.FI || (g[i].FI - pre[i] == curMax.FI && g[i].SE < curMax.SE)) {
			curMax = MP(g[i].FI - pre[i], g[i].SE);
		}
	}
	return g[n];
}

int main() {
	scanf("%d%d", &n, &k);
	REP (i, 1, n + 1) scanf("%d", &a[i]);
	REP (i, 1, n + 1) {
		pre[i] = a[i] + pre[i - 1];
	}
	ll lo = 0, hi = LINF, mid;
	while (lo < hi) {
		mid = hi + lo >> 1;
		pll temp = check(mid);
		if (temp.SE <= k) {
			hi = mid;
		} else {
			lo = mid + 1;
		}
	}
	pll ans = check(hi);
	printf("%lld\n", ans.FI + k * hi);
	return 0;
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:51:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   51 |   mid = hi + lo >> 1;
      |         ~~~^~~~
feast.cpp:44:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   44 |  scanf("%d%d", &n, &k);
      |  ~~~~~^~~~~~~~~~~~~~~~
feast.cpp:45:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   45 |  REP (i, 1, n + 1) scanf("%d", &a[i]);
      |                    ~~~~~^~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29