Submission #144074

#	Time	Username	Problem	Language	Result	Execution time	Memory
144074		liwi	Building Bridges (CEOI17_building)	C++11	0 / 100	158 ms	96632 KiB

building

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;

#define scan(x) do{while((x=getchar())<'0'); for(x-='0'; '0'<=(_=getchar()); x=(x<<3)+(x<<1)+_-'0');}while(0)
char _;
#define complete_unique(a) a.erase(unique(a.begin(),a.end()),a.end())
#define all(a) a.begin(),a.end()
#define println printf("\n");
#define readln(x) getline(cin,x);
#define pb push_back
#define endl "\n"
#define INT_INF 0x3f3f3f3f
#define LL_INF 0x3f3f3f3f3f3f3f3f
#define MOD 1000000007
#define MOD2 1190492669
#define SEED 131
#define mp make_pair
#define fastio cin.tie(0); cin.sync_with_stdio(0);

#define MAXN 100005
#define MAXV 1000005

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef unordered_map<int,int> umii;
typedef pair<int,int> pii;
typedef pair<double,double> pdd;
typedef pair<ll,ll> pll;
typedef pair<int,pii> triple;
typedef int8_t byte;

mt19937 g1(time(0));

int randint(int a, int b){return uniform_int_distribution<int>(a, b)(g1);}
ll randlong(ll a,ll b){return uniform_int_distribution<long long>(a, b)(g1);}

ll gcd(ll a, ll b){return b == 0 ? a : gcd(b, a % b);}
ll lcm(ll a, ll b){return a*b/gcd(a,b);}
ll fpow(ll  b, ll exp, ll mod){if(exp == 0) return 1;ll t = fpow(b,exp/2,mod);if(exp&1) return t*t%mod*b%mod;return t*t%mod;}
ll divmod(ll i, ll j, ll mod){i%=mod,j%=mod;return i*fpow(j,mod-2,mod)%mod;}

struct node{
	int l,r;
	pll bst;
};

struct MinLiChaoTree{
	node seg[4*MAXV];
	inline ll calc(int rt, int m){return seg[rt].bst.first*m+seg[rt].bst.second;}
	inline ll calc(pll bst, int m){return bst.first*m+bst.second;}
	inline ld inter(pll f, pll s){return 1.0*(s.second-f.second)/(f.first-s.first);}
	void build(int l, int r, int rt){
		seg[rt].l = l, seg[rt].r = r, seg[rt].bst = mp(0,LL_INF);
		if(l == r) return;
		int mid = (l+r)/2;
		build(l,mid,rt<<1);
		build(mid+1,r,rt<<1|1);
	}
	void add_line(int rt, pll line){
		if(seg[rt].l == seg[rt].r){
			if(calc(line,seg[rt].l) <= calc(rt,seg[rt].l)) seg[rt].bst = line;
			return;
		}
		int mid = (seg[rt].l+seg[rt].r)/2;
		if(calc(rt,seg[rt].l) < calc(line,seg[rt].l) && calc(rt,seg[rt].r) < calc(line,seg[rt].r)){
			seg[rt].bst = line;
			return;
		}
		ld x = inter(line,seg[rt].bst);
		if(x <= mid){
			if(calc(line,mid) <= calc(rt,mid)) swap(line,seg[rt].bst);
			add_line(rt<<1,line);
		}else{
			if(calc(line,mid) <= calc(rt,mid)) swap(line,seg[rt].bst);
			add_line(rt<<1|1,line);
		}
	}
	ll get(int rt, int pos){
		if(seg[rt].l == seg[rt].r) return calc(rt,pos);
		int mid = (seg[rt].l+seg[rt].r)/2;
		if(pos <= mid) return min(calc(rt,pos),get(rt<<1,pos));
		return min(calc(rt,pos),get(rt<<1|1,pos));
	}
};

int len;
ll dp[MAXN],H[MAXN],W[MAXN];
MinLiChaoTree t;

int main(){
	scanf("%d",&len);
	for(int i=1; i<=len; i++)
		scanf(" %lld",&H[i]);
	for(int i=1; i<=len; i++){
		scanf(" %lld",&W[i]);
		W[i]+=W[i-1];
	}
	t.build(1,1000000,1);
	t.add_line(1,mp(-2LL*H[1],H[1]*H[1]-W[1]));
	for(int i=2; i<=len; i++){
		dp[i] = t.get(1,(int)H[i])+H[i]*H[i]+W[i-1];
		t.add_line(1,mp(-2LL*H[i],dp[i]+H[i]*H[i]-W[i]));
	}
	printf("%lld\n",dp[len]);
}

Compilation message (stderr)

building.cpp: In function 'int main()':
building.cpp:97:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&len);
  ~~~~~^~~~~~~~~~~
building.cpp:99:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf(" %lld",&H[i]);
   ~~~~~^~~~~~~~~~~~~~~
building.cpp:101:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf(" %lld",&W[i]);
   ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40