Submission #1029416

#	Time	Username	Problem	Language	Result	Execution time	Memory
1029416		yeediot	Flooding Wall (BOI24_wall)	C++17	100 / 100	2250 ms	541356 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 = 5e5 + 5, mod = 1e9 + 7;
int n, a[mxn], b[mxn], pw[mxn];
#define s seg[id]
#define L seg[seg[id].lc]
#define R seg[seg[id].rc]
struct node{
    int val, tag, lc, rc;
};
struct segment_tree{
    int tmr = 0;
    vector<node>seg = {{0, 0, 0, 0}};
    void new_node(int l, int r){
        int id = ++tmr;
        seg.pb({0, 0, 0, 0});
        s.val = r - l + 1;
        s.tag = 1;
        s.lc = s.rc = -1;
    }
    void push(int id, int l, int r){
        int mm = (long long) l + r >> 1;
        if(s.lc == -1){
            new_node(l, mm);
            s.lc = tmr;
        }
        if(s.rc == -1){
            new_node(mm + 1, r);
            s.rc = tmr;
        }
        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 merge(int id){
        s.val = ((long long)L.val + R.val) % mod;
    }
    void modify(int l, int r, int id, int ql, int qr, int v){
        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 = (long long) l + r >> 1;
        modify(l, mm, s.lc, ql, qr, v);
        modify(mm + 1, r, s.rc, 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]);
    }
    long long ans = 0;
    segment_tree t1;
    t1.new_node(1, mod);
    for(int i = 1; i <= n; i++){
        t1.modify(1, mod, 1, 1, a[i], 0);
        t1.modify(1, mod, 1, b[i] + 1, mod, 2);
        ans = (ans - (long long)t1.seg[1].val * pw[n - i] % mod) % mod;
    }
    t1.seg.clear();
    t1.tmr = 0;
    t1.seg.pb({0, 0, 0, 0});
    t1.new_node(1, mod);
    for(int i = n; i >= 1; i--){
        t1.modify(1, mod, 1, 1, a[i], 0);
        t1.modify(1, mod, 1, b[i] + 1, mod, 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::push(int, int, int)':
Main.cpp:46:32: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   46 |         int mm = (long long) l + r >> 1;
      |                  ~~~~~~~~~~~~~~^~~
Main.cpp: In member function 'void segment_tree::modify(int, int, int, int, int, int)':
Main.cpp:72:32: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   72 |         int mm = (long long) 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