Submission #1211271

#	Time	Username	Problem	Language	Result	Execution time	Memory
1211271		fafnir	Comparing Plants (IOI20_plants)	C++20	0 / 100	1 ms	328 KiB

plants

#include <bits/stdc++.h>

// #define LOCAL

using namespace std;

const int NMAX = 200'001;

int n,k,q;
int r[NMAX];
int rpref[NMAX+1];


void init(int kl, vector<int> rl) {
    n = rl.size();
    k = kl;
    for (int i = 0; i < n; ++i) {
        r[i] = rl[i];
    }
    rpref[0] = 0;
    for (int i = 1; i <= n; ++i) {
        rpref[i] += rpref[i-1];
        rpref[i] += r[i-1];
    }
}

bool isSmaller(int x, int y) {
    // Two conditions
    // i) r[x] = ... = r[y-1] = 1
    int s0 = rpref[y] - rpref[x];
    if (s0 == (y-1-x+1)) return true;
    //  ii) r[y] = ... = r[n-1] = 1 and r[0] = ... = r[x-1] = 1
    int s1 = rpref[n] - rpref[y+1];
    s1 += rpref[x] - rpref[0];
    if (s1 == 0) return true;

    return false;
}

bool isGreater(int x, int y) {
    // Two conditions
    //   i) r[x] = r[x+1] = ... = r[y-1] = 0
    int s0 = rpref[y] - rpref[x];

    if (s0 == 0) return true;

    
    //  ii) r[y] = ... = r[n-1] = 1 and r[0] = ... = r[x-1] = 1
    int s1 = rpref[n] - rpref[y+1];
    s1 += rpref[x] - rpref[0];
    
    int l1 = (n-1-y);
    l1 += x;


    if (l1 == s1) return true;

    return false;
}

// x, y: Labels of plants
//  Return:
//      1:   x taller than plant y
//     -1:   x smaller than plant y
//      0:   inconclusive
int compare_plants(int x, int y) {
    if (isGreater(x, y)) {
        return 1;
    } else if (isSmaller(x, y)) {
        return -1;
    } else {
        return 0;
    }
}

#ifdef LOCAL

int32_t main() {

    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int nl, kl, ql;
    cin >> nl >> kl >> ql;

    vector<int> rl(nl);
    for (auto& e : rl) cin >> e;

    init(kl, rl);

    for (int _ = 0; _ < ql; _++) {
        int x, y;
        cin >> x >> y;
        cout << compare_plants(x, y);
        if (_ < ql-1) cout << '\n';
    }

    return 0;
}

#endif

• Subtask 1: 0 / 5
• Subtask 2: 0 / 14
• Subtask 3: 0 / 13
• Subtask 4: 0 / 17
• Subtask 5: 0 / 11
• Subtask 6: 0 / 15
• Subtask 7: 0 / 25