Submission #1029951

#	Time	Username	Problem	Language	Result	Execution time	Memory
1029951		yeediot	Flooding Wall (BOI24_wall)	C++17	100 / 100	679 ms	67892 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
#ifdef local
void CHECK();
void setio(){
    freopen("/Users/iantsai/cpp/input.txt","r",stdin);
    freopen("/Users/iantsai/cpp/output.txt","w",stdout);
}
#else
void setio(){}
#endif
#define TOI_is_so_de ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);setio();
const int mxn = 1e6 + 105, mod = 1e9 + 7;
int n, a[mxn], b[mxn], pw[mxn], A[mxn], B[mxn];
#define s seg[id]
#define L seg[id * 2]
#define R seg[id * 2 + 1]
struct node{
    int val, tag;
};
vector<int>temp, v;
struct segment_tree{
    int tmr = 0;
    #ifdef local
    node seg[4000];
    #else
    node seg[4 * mxn];
    #endif
    void merge(int id){
        s.val = ((long long)L.val + R.val) % mod;
    }
    void build(int l, int r, int id){
        s.tag = 1;
        if(l == r){
            s.val = v[l];
            return;
        }
        int mm = l + r >> 1;
        build(l, mm, id * 2);
        build(mm + 1, r, id * 2 + 1);
        merge(id);
    }
    void push(int id, int l, int r){
        L.tag = (long long)L.tag * s.tag % mod;
        R.tag = (long long)R.tag * s.tag % mod;
        L.val = (long long)L.val * s.tag % mod;
        R.val = (long long)R.val * s.tag % mod;
        s.tag = 1;
    }
    void modify(int l, int r, int id, int ql, int qr, int v){
        if(s.tag == 0) return;
        if(qr < l or r < ql) return;
        if(ql <= l and r <= qr){
            s.val = (long long)s.val * v % mod;
            s.tag = (long long)s.tag * v % mod;
            return;
        }
        push(id, l, r);
        int mm = l + r >> 1;
        modify(l, mm, id * 2, ql, qr, v);
        modify(mm + 1, r, id * 2 + 1, ql, qr, v);
        merge(id);
    }
};
void solve(){
    cin >> n;
    pw[0] = 1;
    for(int i = 1; i <= n; i++){
        pw[i] = pw[i - 1] * 2 % mod;
    }
    for(int i = 1; i <= n; i++){
        cin >> a[i];
    }
    for(int i = 1; i <= n; i++){
        cin >> b[i];
        if(a[i] > b[i]) swap(a[i], b[i]);
        temp.pb(a[i]);
        temp.pb(b[i]);
    }
    temp.pb(1);
    temp.pb(0);
    temp.pb(mod);
    sort(all(temp));
    temp.resize(unique(all(temp))-temp.begin());
    int prev = 0;
    for(auto x : temp){
        v.pb(x - prev);
        prev = x;
    }
    for(int i = 1; i <= n; i++){
        A[i] = lower_bound(all(temp), a[i]) - temp.begin();
        B[i] = lower_bound(all(temp), b[i]) - temp.begin();
    }
    long long ans = 0;
    segment_tree t1;
    int N = sz(temp) - 1;
    t1.build(1, N, 1);
    for(int i = 1; i <= n; i++){
        t1.modify(1, N, 1, 1, A[i], 0);
        t1.modify(1, N, 1, B[i] + 1, N, 2);
        ans = (ans - (long long)t1.seg[1].val * pw[n - i] % mod) % mod;
    }
    t1.build(1, N, 1);
    for(int i = n; i >= 1; i--){
        t1.modify(1, N, 1, 1, A[i], 0);
        t1.modify(1, N, 1, B[i] + 1, N, 2);
        ans = (ans - (long long)t1.seg[1].val * pw[i - 1] % mod) % mod;
    }
    ans = ((long long)ans + (long long)n * t1.seg[1].val % mod);
    for(int i = 1; i <= n; i++){
        ans = ((long long)ans + pw[n - 1] * ((long long)b[i] - a[i] + (mod - b[i]) * 2LL % mod)) % mod;
    }
    if(ans < 0) ans += mod;
    cout << ans << '\n';
}
signed main(){
    TOI_is_so_de;
    int t = 1;
    while(t--){
        solve();
    }
}
/*
input:
 
*/

Compilation message (stderr)

Main.cpp: In member function 'void segment_tree::build(int, int, int)':
Main.cpp:52:20: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   52 |         int mm = l + r >> 1;
      |                  ~~^~~
Main.cpp: In member function 'void segment_tree::modify(int, int, int, int, int, int)':
Main.cpp:73:20: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   73 |         int mm = l + r >> 1;
      |                  ~~^~~

• Subtask 1: 8 / 8
• Subtask 2: 17 / 17
• Subtask 3: 19 / 19
• Subtask 4: 14 / 14
• Subtask 5: 12 / 12
• Subtask 6: 30 / 30