Submission #1043663

#	Time	Username	Problem	Language	Result	Execution time	Memory
1043663		YassineBenYounes	Flooding Wall (BOI24_wall)	C++17	25 / 100	5059 ms	2068 KiB

Main

#include<bits/stdc++.h>
//#include<chrono>
//#include<random>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef double db;
ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (PGCD)
ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);} // least common multiple (PPCM)
int dx[8] = {1, 0, 0, -1, 1, 1, -1, -1};
int dy[8] = {0, 1, -1, 0, 1, -1, -1, 1};
#define endl "\n"
#define ss second
#define ff first
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define vi vector<int>
#define vii vector<pair<int,int>>
#define vl vector<ll>
#define vll vector<pair<ll,ll>>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pdd  pair<double,double>
#define vdd  vector<pdd>
#define speed ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define pbds tree<pii, null_type, less<pii>,rb_tree_tag, tree_order_statistics_node_update>
using namespace __gnu_pbds;
using namespace std;
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
////////////////////Only Clear Code//////////////////////////
 
void usaco_problem(){
    freopen("milkvisits.in", "r", stdin);
    freopen("milkvisits.out", "w", stdout);
}
 
void init(){
    #ifndef ONLINE_JUDGE
 
freopen("input.txt", "r", stdin);
 
freopen("output.txt", "w", stdout);
 
#endif // ONLINE_JUDGE
}
const int mx = 1e4+5;
const int LOG = 22;
const int inf = 1e9;
const ll mod = 1e9+7;
const int sq = 320;
int n;
ll a[mx], b[mx];
////0//////1//////
 
int32_t main(){
    speed;
    cin >> n;
    set<ll> s;
    for(int i = 0; i < n;i++){
        cin >> a[i];
        s.insert(a[i]);
    }
    for(int i = 0; i < n;i++){
        cin >> b[i];
        s.insert(b[i]);
        if(a[i] > b[i])swap(a[i], b[i]);
    }
    ll ans = 0;
    for(int i = 1; i < n-1;i++){
        vl v1;
        ll mn1 = -1, mn2 = -1;
        map<ll, ll> mp1, mp2, ans1, ans2;
        for(int j = 0;j < i;j++){
            v1.pb(max(a[j], b[j]));
            mn1 = max(mn1, min(a[j], b[j]));
            //v1.pb({a[j], j, 0});
            //v1.pb({b[j], j, 1});
        }
        sort(all(v1), greater<ll>());
        for(int j = i+1;j < n;j++){
            mn2 = max(mn2, min(a[j], b[j]));
        }
        ll last1 = 0;
        ll gposs1 = 1;
        for(ll x : s){
            while(v1.size() > 0 && v1.back() <= x){
                gposs1 *= 2;
                gposs1 %= mod;
                v1.pop_back();
            }
            ll poss1 = gposs1;
            if(mn1 > x)poss1 = 0;
            mp1[x] = poss1;
            /*for(int k = 0;k < i;k++){
                if(max(a[k], b[k]) <= x){
                    poss1 *= 2;
                    poss1 %= mod;
                }
                if(min(a[k], b[k]) > x){
                    poss1 = 0;
                }
            }*/
            ll cur1 = poss1-last1;
            cur1 %= mod;
            while(cur1 < 0)cur1 += mod;
            ans1[x] = cur1;
            last1 = poss1;
        }
        ll last2 = 0;
        ll gposs2 = 1;
        vl v2;
        for(int j = i+1;j < n;j++){
            v2.pb(max(a[j], b[j]));
        }
        sort(all(v2), greater<ll>());
        for(ll y : s){
            while(v2.size() > 0 && v2.back() <= y){
                gposs2 *= 2;
                gposs2 %= mod;
                v2.pop_back();
            }
            ll poss2 = gposs2;
            if(mn2 > y)poss2 = 0;
            mp2[y] = poss2;

            ll cur2 = poss2 - last2;
            cur2 %= mod;
            while(cur2 < 0)cur2 += mod;
            ans2[y] = cur2;
            last2 = poss2;
        }
        vl v;
        for(ll x : s){
            v.pb(x);
        }
        ll cur2 = 0;
        for(int k = v.size()-1;k >= 0;k--){
            ll cur1 = ans1[v[k]];
            cur2 += ans2[v[k]];
            cur2 %= mod;
            ll p = (cur1*cur2) % mod;
            //cout << v[k].ff << " " << v[k].ss << " " << cur2 << endl;
            ans += (max(0LL, v[k] - a[i])  * p) % mod;
            ans %= mod;
            ans += (max(0LL, v[k] - b[i])  * p) % mod;
            ans %= mod;   
        }
        ll cur1 = 0;
        for(int k = v.size()-1;k >= 0;k--){
            ll cur2 = ans2[v[k]];
            ll p = (cur1*cur2) % mod;
            //cout << v[k].ff << " " << v[k].ss << " " << cur2 << endl;
            ans += (max(0LL, v[k] - a[i])  * p) % mod;
            ans %= mod;
            ans += (max(0LL, v[k] - b[i])  * p) % mod;
            ans %= mod;   
            cur1 += ans1[v[k]];
            cur1 %= mod;
        }
        /*for(ll x : s){
            ll p = (ans1[x] * mp2[x]) % mod;
            ans += (max(0LL, min(x, y) - a[i])  * p) % mod;
            ans %= mod;
            ans += (max(0LL, min(x, y) - b[i])  * p) % mod;
            ans %= mod;
        }*/
    }
    cout << ans << endl;
}
 
/*
    NEVER GIVE UP!
    DOING SMTHNG IS BETTER THAN DOING NTHNG!!!
    Your Guide when stuck:
    - Continue keyword only after reading the whole input
    - Don't use memset with testcases
    - Check for corner cases(n=1, n=0)
    - Check where you declare n(Be careful of declaring it globally and in main)
*/

Compilation message (stderr)

Main.cpp: In function 'void usaco_problem()':
Main.cpp:36:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     freopen("milkvisits.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:37:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     freopen("milkvisits.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp: In function 'void init()':
Main.cpp:43:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 | freopen("input.txt", "r", stdin);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:45:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 | freopen("output.txt", "w", stdout);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 17 / 17
• Subtask 3: 0 / 19
• Subtask 4: 0 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 30