POJ 3104: Drying他

Binary Search

蟻本少しずつ埋めます。

http://poj.org/problem?id=3104

POJ久しぶりにしたので注意点を。(POJ以外の注意点もあり)

  • cout,cinはios::sync_with_stdio(false)にしても遅いのでprintf,scanfを使う。
  • c++11は使えないのでtemplateらへんでcompile errorが生えるのを避ける。
  • accumulateをdoubleで扱いたいなら第3引数を0.0にする。

ACされたコードを丸々載せておく。

#include <iostream>
#include <cmath>
#include <cstdio>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <string.h>
#include <map>
#include <fstream>
#include <functional>
#include <bitset>
#include <stack>
#include <set>
#include <climits>
#include <numeric>
#include <complex>
#define ADD(a, b) a = (a + (ll)b) % mod
#define MUL(a, b) a = (a * (ll)b) % mod
#define MAX(a, b) a = max(a, b)
#define MIN(a, b) a = min(a, b)
#define rep(i, a, b) for(int i = (a); i < (b); i++)
#define rer(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define all(a) (a).begin(), (a).end()
#define sz(v) (int)(v).size()
#define pb push_back
#define sec second
#define fst first
#define debug(fmt, ...) Debug(__LINE__, ":", fmt, ##__VA_ARGS__)
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef pair<int, pi> ppi;
typedef vector<ll> vi;
typedef complex<double> comp;
void Debug() {cout << '\n'; }
template<class FIRST, class... REST>void Debug(FIRST arg, REST... rest) { 
	cout << arg << " "; Debug(rest...); }
template<class T>ostream& operator<< (ostream& out, const vector<T>& v) {
	out << "[";if(!v.empty()){rep(i,0,sz(v)-1)out<<v[i]<< ", ";out<<v.back();}out << "]";return out;}
template<class S, class T>ostream& operator<< (ostream& out, const pair<S, T>& v) {
	out << "(" << v.first << ", " << v.second << ")";return out;}
const int MAX_N = 200010;
const double eps = 1e-6;
const ll mod = 1000000007;
const int inf = 1 << 30;
const ll linf = 1LL << 60;
const double PI = 3.14159265358979323846;
///////////////////////////////////////////////////////////////////////////////////////////////////

int N, C;
ll A[MAX_N];

bool ok(ll m) {
	ll res = 0;
	rep(i, 0, N) {
		if(A[i] - m > 0) res += (A[i] - m + C - 1) / C;
	}
	if(res <= m) return true;
	else return false;
}

void solve() {
	scanf("%d", &N);
	rep(i, 0, N) scanf("%d", &A[i]);
	cin >> C; C--;
	if(C == 0) {
		ll mx  = -1;
		rep(i, 0, N) MAX(mx, A[i]);
		printf("%lld\n", mx);
	}
	else {
		ll lb = -1, ub = (1LL << 60);
		while(ub - lb > 1) {
			ll m = (ub + lb) / 2;
			if(ok(m)) ub = m;
			else lb = m;
		}
		printf("%lld\n", ub);
	}
}

int main() {
	solve();
	return 0;
}