Submission #429783

#	Time	Username	Problem	Language	Result	Execution time	Memory
429783		schse	Handcrafted Gift (IOI20_gift)	C++17	25 / 100	195 ms	21188 KiB

gift

#include "gift.h"
#include <bits/stdc++.h>
using namespace std;
#ifndef EVAL
#include "grader.cpp"
#endif
struct node
{
    int val = -1;
    int substr = 0;
};

struct segtree
{
    vector<node> tree = vector<node>(1 << 20);

    void updset(int index, int b, int e, int l, int r, int v)
    {
        if (l <= b && e <= r)
        {
            tree[index] = {v, 0};
            return;
        }
        if (e <= l || r <= b)
            return;
        {
            if (tree[index * 2].val == -1)
                tree[index * 2].substr += tree[index].substr;
            else
                tree[index * 2].val -= tree[index].substr;

            if (tree[index * 2 + 1].val == -1)
                tree[index * 2 + 1].substr += tree[index].substr;
            else
                tree[index * 2 + 1].val -= tree[index].substr;

            if (tree[index].val != -1)
                tree[index * 2] = tree[index * 2 + 1] = {tree[index].val, 0};
        }
        updset(index * 2, b, (b + e) / 2, l, r, v);
        updset(index * 2 + 1, (b + e) / 2, e, l, r, v);
    }

    void updsubs(int index, int b, int e, int l, int r, int v)
    {
        if (l <= b && e <= r)
        {
            tree[index] = {-1, v};
            return;
        }
        if (e <= l || r <= b)
            return;
        {
            if (tree[index * 2].val == -1)
                tree[index * 2].substr += tree[index].substr;
            else
                tree[index * 2].val -= tree[index].substr;

            if (tree[index * 2 + 1].val == -1)
                tree[index * 2 + 1].substr += tree[index].substr;
            else
                tree[index * 2 + 1].val -= tree[index].substr;

            if (tree[index].val != -1)
                tree[index * 2] = tree[index * 2 + 1] = {tree[index].val, 0};
        }
        updsubs(index * 2, b, (b + e) / 2, l, r, v);
        updsubs(index * 2 + 1, (b + e) / 2, e, l, r, v);
    }

    int query(int index, int b, int e, int p)
    {
        if (p < b || p >= e)
            return 0;
        if (e - b == 1)
            return tree[index].val;
        return query(index * 2, b, (b + e) / 2, p) + query(index * 2 + 1, (b + e) / 2, e, p);
    }
} tree;

int construct(int n, int r, std::vector<int> a, std::vector<int> b, std::vector<int> x)
{

    int sb = 0;
    for (int i : x)
        sb |= i;
    if (sb == 1)
    {
        std::string s(n, 'R');
        craft(s);
        return 1;
    }
    else if (sb == 2)
    {
        for (int i = 0; i < a.size(); i++)
            if (a[i] == b[i])
                return 0;
        std::string s(n, 'R');
        for (int i = 0; i < n; i++)
            s[i] = i % 2 ? 'R' : 'B';
        craft(s);
        return 1;
    }
    else
    {
        for (int i = 0; i < n; i++)
            tree.updset(1, 0, n, i, i + 1, i);

        vector<int> prefix(n);
        iota(prefix.begin(), prefix.end(), 0);
        for (int i = 0; i < a.size(); i++) //update single color
        {
            if (x[i] == 1)
            {
                int va = tree.query(1, 0, n, a[i]);
                int vb = tree.query(1, 0, n, b[i]);
                tree.updset(1, 0, n, a[i], b[i], va);
                tree.updsubs(1, 0, n, b[i], n, vb - va);
/*
                for (int e = b[i] + 1; e < n; e++)
                    prefix[e] -= prefix[b[i]] - prefix[a[i]];
                for (int e = a[i] + 1; e < b[i] + 1; e++)
                    prefix[e] = prefix[a[i]];
  */          }
        }

        for (int i = 0; i < a.size(); i++) //check wetherpossible
        {
            if (x[i] == 2)
            {
                int va = tree.query(1, 0, n, a[i]);
                int vb = tree.query(1, 0, n, b[i]);
                if (vb - va < 1)
                    return 0;
                /*if (prefix[b[i]] - prefix[a[i]] < 1)
                    return 0;*/
            }
        }
        std::string s(n, 'R');
        for (int i = 0; i < n; i++)
            s[i] = tree.query(1, 0, n, i) % 2 ? 'R' : 'B';
        craft(s);
        return 1;
    }
}

Compilation message (stderr)

gift.cpp: In function 'int construct(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
gift.cpp:95:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   95 |         for (int i = 0; i < a.size(); i++)
      |                         ~~^~~~~~~~~~
gift.cpp:111:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |         for (int i = 0; i < a.size(); i++) //update single color
      |                         ~~^~~~~~~~~~
gift.cpp:127:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  127 |         for (int i = 0; i < a.size(); i++) //check wetherpossible
      |                         ~~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 0 / 20
• Subtask 4: 0 / 25
• Subtask 5: 0 / 30