Submission #635346

#	Time	Username	Problem	Language	Result	Execution time	Memory
635346		radal	Remittance (JOI19_remittance)	C++17	15 / 100	270 ms	340 KiB

remittance

#include <bits/stdc++.h>
#pragma GCC target("sse,sse2")
#pragma GCC optimize("unroll-loops,O3")
#define rep(i,l,r) for (int i = l; i < r; i++)
#define repr(i,r,l) for (int i = r; i >= l; i--)
#define X first
#define Y second
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define endl '\n'
#define debug(x) cerr << #x << " : " << x << endl;
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pll;
constexpr int N = 1e6+20,mod = 1e9+7,inf = 1e9+10;
inline int mkay(int a,int b){
    if (a+b >= mod) return a+b-mod;
    if (a+b < 0) return a+b+mod;
    return a+b;
}
 
inline int poww(int a,int k){
    if (k < 0) return 0;
    int z = 1;
    while (k){
        if (k&1) z = 1ll*z*a%mod;
        a = 1ll*a*a%mod;
        k /= 2;
    } 
    return z; 
}

int a[N],b[N],n,x[N],j,tmp[N];
ll s,s2;
int nxt(int i){
    return ((i == n-1) ? 0 : i+1);
}

bool check(int val){
    s2 = val;
    if (s2 > s) return 0;
    x[j] = val;
    int cur = j;
    do{
        int k = nxt(cur);
        if  (k == j) break;
        if ((a[cur]-b[cur]+x[cur])%2 || a[cur]-b[cur] < -x[cur]){
            return 0;
        }
        x[k] = (a[cur]-b[cur]+x[cur])/2;
        s2 += x[k];
        if (s2 > s) return 0;
        cur = k;
    }while (1);
    if (s != s2) return 0;
    return 1;
}

bool check2(){
    rep(i,0,n) tmp[i] = a[i];
    while (1){
        bool fl = 0;
        rep(i,0,n) fl |= x[i];
        if (!fl) return 1;
        rep(i,0,n){
            int k = nxt(i);
            if (!x[k] || tmp[i] <= 1) continue;
            fl = 0;
            if (tmp[i] >= 2*x[k]){
                tmp[i] -= 2*x[k];
                tmp[k] += 2*x[k];
                x[k] = 0;
            }
            else{
                int cnt = tmp[i]/2;
                tmp[i] -= 2*cnt;
                x[k] -= cnt;
                tmp[k] += cnt;
            }
        }
        if (fl) return 0;
    }
}
int main(){
    ios_base :: sync_with_stdio(0); cin.tie(0);
    cin >> n;
    int mx = -1;
    rep(i,0,n){
        cin >> a[i] >> b[i];
        s += a[i]-b[i];
        if (a[i]-b[i] > mx){
            j = i;
            mx = a[i]-b[i];
        }
    }
    if (s < 0){
        cout << "No";
        return 0;
    }
    rep(i,0,50000000) if (check(i) && check2()){
        cout << "Yes";
        return 0;
    }
    cout << "No";
    return 0;
}

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