Submission #1105933

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105933		RiverFlow	Towers (NOI22_towers)	C++14	100 / 100	695 ms	120356 KiB

Main

#include <bits/stdc++.h>

#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())

using namespace std;

template<typename U, typename V> bool maxi(U &a, V b) {
    if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
    if (a > b) { a = b; return 1; } return 0;
}

const int mod = (int)1e9 + 7;

void prepare(); void main_code();

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    const bool MULTITEST = 0; prepare();
    int num_test = 1; if (MULTITEST) cin >> num_test;
    while (num_test--) { main_code(); }
}

void prepare() {};

const int N = (int)1e6 + 9;

struct point {
    int x, y;
};

point a[N];

pair<int, int> b[N];

vector<int> row[N];

vec<int> col[N];

void _fill(int rw, int j) {
    int c = a[j].x;
    col[c].push_back(j);
    sort(all(col[c]), [&](int x, int y){
         return a[x].y < a[y].y;
    });
    if (sz(col[c]) == 3) {
        swap(col[c][1], col[c][2]);
        int t = col[c].back();
        col[c].pop_back();
        int nw = a[t].y;
        int &l = b[nw].fi, &r = b[nw].se;
        if (row[nw][l] == t) {
            ++l;
            if (l<r)
                _fill(nw, row[nw][l]);
        } else {
            --r;
            if (r>l)
                _fill(nw, row[nw][r]);
        }
    }

}
void main_code() {
    int n; cin >> n;
    vec<int> yy;
    for(int i = 0; i < n; ++i) {
        cin >> a[i].x >> a[i].y;
        row[a[i].y].push_back(i);
    }
    const int MAX = N - 3;
    FOR(i, 0, MAX) if (sz(row[i])) {
        sort(row[i].begin(), row[i].end(), [&](int x, int y) {
             return a[x].x < a[y].x;
        });
        int m = sz(row[i]);
        b[i] = _mp(0, m - 1);
        _fill(i, row[i][0]);
        if (m != 1)
            _fill(i, row[i][m - 1]);
    }
    vec<bool> use(n, 0);
    FOR(i, 0, MAX) if (sz(row[i])) {
        int l=b[i].fi, r=b[i].se;
        if (l<=r){
            use[row[i][l]]=use[row[i][r]]=1;
        }
    }
    string s;
    FOR(i,0,n-1){
        if(use[i])s.push_back('1');
        else s.push_back('0');
    }
    cout << s;

}


/*     Let the river flows naturally     */

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 11 / 11
• Subtask 3: 7 / 7
• Subtask 4: 6 / 6
• Subtask 5: 31 / 31
• Subtask 6: 21 / 21
• Subtask 7: 19 / 19