Submission #3452974
Source Code Expand
#include <bits/stdc++.h>
using namespace std;
#define NDEBUG
#ifdef DEBUG
#include "../cout11.h"
#undef NDEBUG
#endif
#include <cassert>
typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;
#define sz(a) int((a).size())
#define pb push_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n) for(int var=0;var<(n);++var)
#define rep1(var,n) for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n) for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define ALL(c) (c).begin(),(c).end()
#define RALL(c) (c).rbegin(),(c).rend()
#define tr(i,c) for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e) ((s).find(e)!=(s).end())
#define mset(arr,val) memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))
#define cons make_pair
ll gcd(ll a, ll b) { while(a) swap(a, b%=a); return b; }
const ll MOD=1000000007LL;
ll ADD(ll x, ll y) { return (x+y) % MOD; }
ll SUB(ll x, ll y) { return (x-y+MOD) % MOD; }
ll MUL(ll x, ll y) { return x*y % MOD; }
ll POW(ll x, ll e) { ll v=1; for(; e; x=MUL(x,x), e>>=1) if (e&1) v = MUL(v,x); return v; }
ll DIV(ll x, ll y) { /*assert(y%MOD!=0);*/ return MUL(x, POW(y, MOD-2)); }
// ll comb(ll n, ll k) { ll v=1; for(ll i=1; i<=k; i++) v = DIV(MUL(v, n-i+1),i); return v; }
//
ll FACT(ll n) {
ll fact_n = 1LL;
rep1(i,n) fact_n = MUL(fact_n, i);
return fact_n;
}
#define INTSPACE 12
char _buf[INTSPACE*1000000 + 3];
int loadint() {
if (fgets(_buf, INTSPACE+3, stdin)==NULL) return 0;
return atoi(_buf);
}
int loadvec(vector<int>& v, int N=-1) {
if (N == -1) {
N = loadint();
if (N==0) return 0;
}
int bufsize = INTSPACE*N + 3;
if (fgets(_buf, bufsize, stdin)==NULL) return 0;
v.resize(N);
int i=0;
bool last = false;
for (char *p=&_buf[0]; ;) {
char *q = p;
while (*q > ' ') ++q;
if (*q == 0x0D || *q == 0x0A) last = true;
*q = 0;
v[i++] = atoi(p);
if (last || i == N) break;
p = q+1;
}
// assert(i <= N);
return i;
}
void read_cr() {
fgets(_buf, 256, stdin);
}
ll solve(int N, vi& a) {
vector<ll> inv(N+1);
for (int n=1; n<=N; ++n) inv[n] = DIV(1, n);
vector<ll> inv_acc(N+1, 0);
for (int n=1; n<=N; ++n) inv_acc[n] = inv_acc[n-1] + inv[n];
#ifdef DEBUG
cerr << inv << endl;
cerr << inv_acc << endl;
#endif
ll fact_n = FACT(N);
ll ans = 0;
rep(i,N){
ll p = ADD(SUB(inv_acc[N-i], inv_acc[0]),
SUB(inv_acc[1+i], inv_acc[1]));
// fprintf(stderr, "i=%d: p=%lld\n", i, p);
ans = ADD(ans, MUL(p, a[i]));
}
ans = MUL(ans, fact_n);
return ans;
}
double solve_f(int N, vi& a) {
vector<double> inv(N + 1);
for (int n = 1; n <= N; ++n) inv[n] = 1.0 / n;
vector<double> inv_acc(N + 1, 0);
for (int n = 1; n <= N; ++n) inv_acc[n] = inv_acc[n - 1] + inv[n];
#ifdef DEBUG
cerr << inv << endl;
cerr << inv_acc << endl;
#endif
// ll fact_n = FACT(N);
double fact_n = 1.0; rep1(i,N) fact_n *= i;
double ans = 0;
rep(i, N) {
double p = (inv_acc[N - i] - inv_acc[0])
+ (inv_acc[1 + i] - inv_acc[1]);
// fprintf(stderr, "i=%d: p=%g\n", i, p);
ans += p * a[i];
}
ans *= fact_n;
return ans;
}
int main() {
vi a;
int N = loadvec(a);
cout << solve(N,a) << endl;
// cout << solve_f(N,a) << endl;
return 0;
}
Submission Info
Submission Time
2018-10-22 23:12:44+0900
Task
B - Removing Blocks
User
naoya_t
Language
C++14 (GCC 5.4.1)
Score
600
Code Size
3920 Byte
Status
AC
Exec Time
23 ms
Memory
3200 KB
Compile Error
./Main.cpp: In function ‘void read_cr()’:
./Main.cpp:92:28: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
fgets(_buf, 256, stdin);
^
Judge Result
Set Name
Sample
All
Score / Max Score
0 / 0
600 / 600
Status
Set Name
Test Cases
Sample
sample-01.txt, sample-02.txt, sample-03.txt
All
sample-01.txt, sample-02.txt, sample-03.txt, sample-01.txt, sample-02.txt, sample-03.txt, subtask01-01.txt, subtask01-02.txt, subtask01-03.txt, subtask01-04.txt, subtask01-05.txt, subtask01-06.txt, subtask01-07.txt, subtask01-08.txt, subtask01-09.txt, subtask01-10.txt, subtask01-11.txt, subtask01-12.txt, subtask01-13.txt
Case Name
Status
Exec Time
Memory
sample-01.txt
AC
1 ms
256 KB
sample-02.txt
AC
1 ms
256 KB
sample-03.txt
AC
1 ms
256 KB
subtask01-01.txt
AC
1 ms
256 KB
subtask01-02.txt
AC
17 ms
2432 KB
subtask01-03.txt
AC
14 ms
1920 KB
subtask01-04.txt
AC
17 ms
2432 KB
subtask01-05.txt
AC
6 ms
896 KB
subtask01-06.txt
AC
10 ms
1408 KB
subtask01-07.txt
AC
6 ms
896 KB
subtask01-08.txt
AC
23 ms
3200 KB
subtask01-09.txt
AC
23 ms
3200 KB
subtask01-10.txt
AC
23 ms
3200 KB
subtask01-11.txt
AC
23 ms
3200 KB
subtask01-12.txt
AC
23 ms
3200 KB
subtask01-13.txt
AC
23 ms
3200 KB