#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define MANY_TESTS int tcase; cin >> tcase; while(tcase--)
const double EPS = 1e-9;
const int MOD = 1e9+7;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {1, 0, -1, 0, -1, 1, 1, -1};
const vi dx = {0, 1, 0, -1, -1, 1, -1, 1};
void DBG(){cout << "]" << endl;}
template<typename T, typename ...U> void DBG(const T& head, const U... args){ cout << head << "; "; DBG(args...); }
#define dbg(...) cout << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__);
#define chk() cout << "Check at line(" << __LINE__ << ") hit." << endl;
template<class T, unsigned int U>
ostream& operator<<(ostream& out, const array<T, U> &v){out << "["; REP(i, U) out << v[i] << ", "; out << "]"; return out;}
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "["; REP(i, v.size()) out << v[i] << ", "; out << "]"; return out;}
template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }
const int mod = (int)1e9+7;
struct Mint{
int val;
Mint(){ val = 0; }
Mint(long long v){
val = (-mod <= v && v < mod) ? v : v%mod;
if(val < 0) val+= mod;
}
// operators
Mint operator-(){return Mint(-val);}
Mint& operator+=(const Mint& other){ val+=other.val; if(val >= mod) val-=mod; return *this;}
Mint& operator-=(const Mint& other){ val-=other.val; if(val < 0) val+=mod; return *this;}
Mint& operator*=(const Mint& other){ val=((long long)val*other.val)%mod; return *this;}
friend Mint binpow(Mint a, long long p){
Mint res(1);
while(p > 0){
if(p&1) res*=a; a*=a; p>>=1;
}
return res;
}
friend Mint inv(Mint a){ return binpow(a, mod-2); }
Mint& operator/=(const Mint &other){ return (*this)*=inv(other);}
friend Mint operator+(Mint a, const Mint& b){ return a+=b; }
friend Mint operator-(Mint a, const Mint& b){ return a-=b; }
friend Mint operator*(Mint a, const Mint& b){ return a*=b; }
friend Mint operator/(Mint a, const Mint& b){ return a/=b; }
bool operator==(const Mint &other){return val == other.val;}
bool operator!=(const Mint &other){return val != other.val;}
bool operator<(const Mint &other){return val < other.val;}
// io
friend ostream& operator<<(ostream &out, Mint &a){ return out << a.val; }
};
Mint get_rect(int h, int w, int h_orig){
// upper part
Mint indiv = Mint(1ll * h * w);
Mint slice = Mint(1ll * h * w) * Mint(h + w - 2);
slice /= Mint(2);
Mint other = Mint(1ll * h * w) * Mint(1ll * h * w - (h + w - 1));
other /= Mint(4);
// lower part
Mint topslice = Mint(w) * Mint(h) * Mint(h_orig - h);
Mint top_other = Mint(1ll * w * h) * Mint(1ll * (w - 1) * (h_orig - h));
top_other /= Mint(2);
Mint res = indiv + slice + other + topslice + top_other;
return res;
}
struct dsu{
vector<int> p;
vector<int> w;
vector<int> h;
vector<int> la;
vector<int> ra;
vector<array<int, 2>> largest;
int n;
dsu(int _n, vector<int> _h, vector<int> _w) : n(_n){
p.resize(n, -1);
w.resize(n);
REP(i, n)
w[i] = _w[i];
h.resize(n);
REP(i, n)
h[i] = _h[i];
REP(i, n)
largest.pb({_h[i], i});
sort(all(largest));
reverse(all(largest));
la.resize(n);
ra.resize(n);
REP(i, n){
la[i] = i - 1;
}
REP(i, n){
ra[i] = i + 1;
}
ra[n - 1] = -1;
}
int find(int x){
if(x == -1) return -1;
return (p[x] < 0 ? x : (p[x] = find(p[x])));
}
void join(int a, int b){
a = find(a);
b = find(b);
la[b] = la[a];
h[b] = min(h[a], h[b]);
w[b] = w[a] + w[b];
p[a] = b;
}
Mint go(int num){
array<int, 2> tp = largest[num];
int id = tp[1]; id = find(id);
int left = la[id]; int right = ra[id];
left = find(left); right = find(right);
if(left == -1 && right == -1){
return get_rect(h[id], w[id], h[id]);
}
else if(left == -1){
Mint ans = get_rect(h[id] - h[right], w[id], h[id]);
join(id, right);
return ans;
}
else if(right == -1){
Mint ans = get_rect(h[id] - h[left], w[id], h[id]);
join(left, id);
return ans;
}
else{
if(h[left] >= h[right]){
Mint ans = get_rect(h[id] - h[left], w[id], h[id]);
join(left, id);
return ans;
}
else{
Mint ans = get_rect(h[id] - h[right], w[id], h[id]);
join(id, right);
return ans;
}
}
}
};
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
int n; cin >> n;
vector<int> h(n);
cin >> h;
vector<int> w(n);
cin >> w;
Mint ans(0);
dsu d(n, h, w);
REP(i, n){
ans = ans + d.go(i);
}
cout << ans.val << "\n";
return 0;
}
Compilation message
fancyfence.cpp: In function 'Mint binpow(Mint, long long int)':
fancyfence.cpp:73:13: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
73 | if(p&1) res*=a; a*=a; p>>=1;
| ^~
fancyfence.cpp:73:29: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
73 | if(p&1) res*=a; a*=a; p>>=1;
| ^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
364 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
384 KB |
Output is correct |
| 2 |
Correct |
1 ms |
364 KB |
Output is correct |
| 3 |
Correct |
1 ms |
364 KB |
Output is correct |
| 4 |
Correct |
1 ms |
364 KB |
Output is correct |
| 5 |
Correct |
1 ms |
364 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
512 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
364 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
492 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
364 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
364 KB |
Output isn't correct |
