Submission #615523

#	Time	Username	Problem	Language	Result	Execution time	Memory
615523		HediChehaidar	Remittance (JOI19_remittance)	C++17	0 / 100	1 ms	316 KiB

remittance

#include<bits/stdc++.h>
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)
#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 dte  tuple<double , double , double>
using namespace std;
const int INF = 1000*1000*1000; // 1 e 9
const int MOD = 1e9 + 7;//998244353 ;
const double EPS = 0.000000001; // 1 e -9
const ll inf = (ll)1e18;

bool vis[22];
bool ok = true;
int n;
pll p[22];
void dfs(int pos , ll need){
    //cout << pos <<  " " << need << "\n";
    int i = pos;
    if(vis[pos]) {
        ok = false; return;
    }
    vis[pos] = true;
    ll cur = p[i].ff - p[i].ss;
    if(cur >= need) {
        p[i].ff -= need; return;
    }
    ll nxt = (need - max((ll)0 , p[i].ff - p[i].ss) + max((ll)0 , p[i].ss - p[i].ff)) * 2;
    int id = pos - 1; if(id == -1) id = n - 1;
    dfs(id , nxt);
    p[i].ff = p[i].ss;
}
int main(){
    //ifstream fin ("testing.txt");
    //ofstream fout ("output.txt");
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    cin>>n;
    if(n > 20) return 0;
    for(int i = 0 ; i < n ; i++) cin>>p[i].ff>>p[i].ss;
    for(int i = 0 ; i < n ; i++){
        if(p[i].ff < p[i].ss){
            memset(vis , 0 , sizeof vis);
            ok = true;
            dfs(i , 0);
            if(!ok) return cout << "No\n",0;
        }
    }
    for(int i = 0 ; i < n ; i++){
        if(p[i].ff != p[i].ss) return cout << "No\n",0;
    }
    cout << "Yes\n";
    return 0;
}

/*
    Think of : BS / DFS / BFS / SSSP / SCC / MSP / MAX FLOW / TOPSORT / LCA / MATRIX / DP(bitmask) / 2 POINTERS / SEG TREE / MATH / UN FIND / MO / HLD
    Read the statement CAREFULLY !!
    Make a GREADY APPROACH !!!! (start from highest / lowest)
    Make your own TESTS !!
    Be careful from CORNER CASES !
*/

• Subtask 1: 0 / 15
• Subtask 2: 0 / 40
• Subtask 3: 0 / 45