Submission #322245

#	Time	Username	Problem	Language	Result	Execution time	Memory
322245		dolphingarlic	Swap (BOI16_swap)	C++14	68 / 100	777 ms	262148 KiB

swap

#include <bits/stdc++.h>
using namespace std;

int a[200002];
bool needed[200002][18][2];
vector<int> dp[200002][18][2], tmp;

void merge(vector<int> &ret, vector<int> &l, vector<int> &r) {
    for (int i = 0, j = 1; i < l.size(); i += j, j <<= 1) {
        for (int k = i; k < i + j && k < l.size(); k++) ret.push_back(l[k]);
        for (int k = i; k < i + j && k < r.size(); k++) ret.push_back(r[k]);
    }
}

int main() {
    int n;
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) scanf("%d", a + i);

    needed[1][0][1] = true;
    for (int node = n; node; node--) {
        for (int i = 0; node >> i; i++) for (int j : {0, 1}) {
            if (node * 2 >= n || !(((node >> i + 1) << 1) + j)) continue;
            int val = a[((node >> i + 1) << 1) + j];
            int mn = min({val, a[2 * node], a[2 * node + 1]});
            if (mn == val) {
                needed[2 * node][0][0] = needed[2 * node + 1][0][1] = true;
            } else if (mn == a[2 * node]) {
                needed[2 * node][i + 1][j] = needed[2 * node + 1][0][1] = true;
            } else {
                needed[2 * node][0][0] = needed[2 * node][i + 1][j] = true;
                needed[2 * node + 1][0][0] = needed[2 * node + 1][i + 1][j] = true;
            }
        }
    }


    for (int node = n; node; node--) {
        for (int i = 0; node >> i; i++) for (int j : {0, 1}) {
            if (!needed[node][i][j]) continue;
            int val = a[((node >> i + 1) << 1) + j];

            if (node * 2 > n) dp[node][i][j] = {val};
            else if (node * 2 == n) {
                if (val < a[2 * node]) dp[node][i][j] = {val, a[2 * node]};
                else dp[node][i][j] = {a[2 * node], val};
            } else {
                int mn = min({val, a[2 * node], a[2 * node + 1]});
                if (mn == val) {
                    dp[node][i][j] = {val};
                    merge(dp[node][i][j], dp[2 * node][0][0], dp[2 * node + 1][0][1]);
                } else if (mn == a[2 * node]) {
                    dp[node][i][j] = {a[2 * node]};
                    merge(dp[node][i][j], dp[2 * node][i + 1][j], dp[2 * node + 1][0][1]);
                } else {
                    dp[node][i][j] = tmp = {a[2 * node + 1]};
                    merge(dp[node][i][j], dp[2 * node][0][0], dp[2 * node + 1][i + 1][j]);
                    merge(tmp, dp[2 * node][i + 1][j], dp[2 * node + 1][0][0]);
                    dp[node][i][j] = min(dp[node][i][j], tmp);
                }
                vector<int>().swap(dp[2 * node][i + 1][j]);
                vector<int>().swap(dp[2 * node + 1][i + 1][j]);
            }
        }
        if (node * 2 <= n) {
            vector<int>().swap(dp[node * 2][0][0]);
            vector<int>().swap(dp[node * 2][0][1]);
            vector<int>().swap(dp[node * 2 + 1][0][0]);
            vector<int>().swap(dp[node * 2 + 1][0][1]);
        }
    }

    for (int i : dp[1][0][1]) printf("%d ", i);
    return 0;
}

Compilation message (stderr)

swap.cpp: In function 'void merge(std::vector<int>&, std::vector<int>&, std::vector<int>&)':
swap.cpp:9:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |     for (int i = 0, j = 1; i < l.size(); i += j, j <<= 1) {
      |                            ~~^~~~~~~~~~
swap.cpp:10:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |         for (int k = i; k < i + j && k < l.size(); k++) ret.push_back(l[k]);
      |                                      ~~^~~~~~~~~~
swap.cpp:11:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |         for (int k = i; k < i + j && k < r.size(); k++) ret.push_back(r[k]);
      |                                      ~~^~~~~~~~~~
swap.cpp: In function 'int main()':
swap.cpp:23:48: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   23 |             if (node * 2 >= n || !(((node >> i + 1) << 1) + j)) continue;
      |                                              ~~^~~
swap.cpp:24:37: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   24 |             int val = a[((node >> i + 1) << 1) + j];
      |                                   ~~^~~
swap.cpp:41:37: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   41 |             int val = a[((node >> i + 1) << 1) + j];
      |                                   ~~^~~
swap.cpp:17:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   17 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
swap.cpp:18:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   18 |     for (int i = 1; i <= n; i++) scanf("%d", a + i);
      |                                  ~~~~~^~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 11 / 11
• Subtask 3: 27 / 27
• Subtask 4: 20 / 20
• Subtask 5: 0 / 32