Submission #4065094


Source Code Expand

#include <bits/stdc++.h>
using namespace std;
struct Fast {Fast(){std::cin.tie(0);ios::sync_with_stdio(false);cout.precision(20);}} fast;

/* define */
#define FOR(I,X,Y) for(long long (I)=(X);(I)<(Y);(I)++)
#define REP(I,X,Y) for(long long (I)=(Y)-1;(I)>=(X);(I)--)
#define ALL(X) (X).begin(),(X).end()
#define pb push_back
#define COUNT(V,X) (upper_bound((V).begin(),(V).end(),X)-lower_bound((V).begin(),(V).end(),X))
#define debug(x) cerr<<#x<<':'<<x<<endl;
#define DEBUG(v) cerr<<#v<<':';for(auto xXx:v)cerr<<xXx<<' ';cerr<<endl;
#define Yes(X) if(X){cout<<"Yes"<<endl;}else{cout<<"No"<<endl;}
#define YES(X) if(X){cout<<"YES"<<endl;}else{cout<<"NO"<<endl;}
#define ctoi(C) (C-'0')

/* alias */
using ll = long long;
using ld = long double;
using vi = vector<int>;
using vii = vector<vector<int>>;
using vl = vector<long long>;
using vll = vector<vector<long long>>;
using pi = pair<int,int>;
using pl = pair<long long,long long>;
template<typename T> using PQ = priority_queue<T>;
template<typename T> using minPQ = priority_queue<T, vector<T>, greater<T>>;

/* const */
const long long dx[] = {1,0,-1,0};
const long long dy[] = {0,1,0,-1};
const long long dx8[] = {1,1,0,-1,-1,-1,0,1};
const long long dy8[] = {0,1,1,1,0,-1,-1,-1};
const long long dx9[] = {1,1,0,-1,-1,-1,0,1,0};
const long long dy9[] = {0,1,1,1,0,-1,-1,-1,0};
const int INF = 1000000007;
const long long LINF = 1000000000000000007;

/* func */
template <typename T> inline bool chmin(T& a, const T& b) {if (a > b) a = b; return a > b;}
template <typename T> inline bool chmax(T& a, const T& b) {if (a < b) a = b; return a < b;}
long long max(long long x,int y){return max(x,(long long)y);}
long long max(int x,long long y){return max((long long)x,y);}
long long min(long long x,int y){return min(x,(long long)y);}
long long min(int x,long long y){return min((long long)x,y);}

/* liblary */



/* main */

ld func(ld& speed,ld t,ld max,ld lastspeed){
    ld firstspeed = speed;
    if(max <= lastspeed){
        speed = min(speed+t,max);
        if(max == speed){
            return speed*t - (max-firstspeed)*(max-firstspeed)/2;
        }
        else{
            return firstspeed*t + t*t/2;
        }
    }
    if(firstspeed+t <= lastspeed){
        speed = firstspeed+t;
        return firstspeed*t + t*t/2;
    }
    if((firstspeed+lastspeed+t)/2 <= max){
        speed = lastspeed;
        ld t_first = (lastspeed-firstspeed+t)/2;
        ld t_second = t-t_first;
        ld first = firstspeed*t_first + t_first*t_first/2;
        ld second = lastspeed*t_second + t_second*t_second/2;
        return first + second;
    }
    speed = lastspeed;
    ld t_first = max-firstspeed;
    ld t_third = max-lastspeed;
    ld t_second = t - t_first - t_third;
    ld first = firstspeed*t_first + t_first*t_first/2;
    ld second = max*t_second;
    ld third = lastspeed*t_third + t_third*t_third/2;
    return first+second+third;
}

/*
y = firstspeed + x;
y = t-x + lastspeed;
firstspeed + x = t-x + lastspeed;
x = (lastspeed-firstspeed+t)/2;
y = (firstspeed+lastspeed+t)/2;
*/

signed main(){
    ll N;
    cin >> N;
    ld t[N+2]={0},v[N+2]={0};
    FOR(i,0,N)cin >> t[i+1];
    FOR(i,0,N)cin >> v[i+1];
    REP(i,1,N+1)chmin(v[i],v[i+1]+t[i]);
    ld ans = 0;
    ld speed = 0;
    FOR(i,1,N+1){
        ans += func(speed,t[i],v[i],v[i+1]);
    }
    cout << ans << endl;
}

Submission Info

Submission Time
Task D - AtCoder Express
User nu50218
Language C++14 (GCC 5.4.1)
Score 400
Code Size 3454 Byte
Status AC
Exec Time 2 ms
Memory 384 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 400 / 400
Status
AC × 5
AC × 40
Set Name Test Cases
Sample s1.txt, s2.txt, s3.txt, s4.txt, s5.txt
All in01.txt, in02.txt, in03.txt, in04.txt, in05.txt, in06.txt, in07.txt, in08.txt, in09.txt, in10.txt, in11.txt, in12.txt, in13.txt, in14.txt, in15.txt, in16.txt, in17.txt, in18.txt, in19.txt, in20.txt, in21.txt, in22.txt, in23.txt, in24.txt, in25.txt, in26.txt, in27.txt, in28.txt, in29.txt, in30.txt, in31.txt, in32.txt, in33.txt, in34.txt, in35.txt, s1.txt, s2.txt, s3.txt, s4.txt, s5.txt
Case Name Status Exec Time Memory
in01.txt AC 2 ms 384 KB
in02.txt AC 1 ms 256 KB
in03.txt AC 1 ms 256 KB
in04.txt AC 1 ms 256 KB
in05.txt AC 1 ms 256 KB
in06.txt AC 1 ms 256 KB
in07.txt AC 1 ms 256 KB
in08.txt AC 1 ms 256 KB
in09.txt AC 1 ms 256 KB
in10.txt AC 1 ms 256 KB
in11.txt AC 1 ms 256 KB
in12.txt AC 1 ms 256 KB
in13.txt AC 1 ms 256 KB
in14.txt AC 1 ms 256 KB
in15.txt AC 1 ms 256 KB
in16.txt AC 1 ms 256 KB
in17.txt AC 1 ms 256 KB
in18.txt AC 1 ms 256 KB
in19.txt AC 1 ms 256 KB
in20.txt AC 1 ms 256 KB
in21.txt AC 1 ms 256 KB
in22.txt AC 1 ms 256 KB
in23.txt AC 1 ms 256 KB
in24.txt AC 1 ms 256 KB
in25.txt AC 1 ms 256 KB
in26.txt AC 1 ms 256 KB
in27.txt AC 1 ms 256 KB
in28.txt AC 1 ms 256 KB
in29.txt AC 1 ms 256 KB
in30.txt AC 1 ms 256 KB
in31.txt AC 1 ms 256 KB
in32.txt AC 1 ms 256 KB
in33.txt AC 1 ms 256 KB
in34.txt AC 1 ms 256 KB
in35.txt AC 1 ms 256 KB
s1.txt AC 1 ms 256 KB
s2.txt AC 1 ms 256 KB
s3.txt AC 1 ms 256 KB
s4.txt AC 1 ms 256 KB
s5.txt AC 1 ms 256 KB