Submission #27104

#	Time	Username	Problem	Language	Result	Execution time	Memory
27104		tlwpdus	Swap (BOI16_swap)	C++11	100 / 100	79 ms	6708 KiB

swap

#include <bits/stdc++.h>

using namespace std;

int n, arr[400100], brr[400100], used[400100], INF = 987654321;

int getv(int idx) {
    int res = INF;
    while(idx>0) {
        if (used[idx]!=1) res = min(res,arr[idx]);
        if (!used[idx]) break;
        if ((idx&1)&&used[idx^1]) {
            res = min(res,arr[idx^1]);
            if (used[idx^1]==1) break;
        }
        idx>>=1;
    }
    return res;
}

void era(int idx, int val) {
    while(idx>0) {
        if (arr[idx]==val) {
            used[idx] = 0;
            break;
        }
        if (idx&1) {
            if (arr[idx^1]==val) {
                used[idx^1] = used[idx] = 1;
                break;
            }
            else used[idx^1] = 0;
        }
        used[idx] = 1;
        idx>>=1;
    }
}

int main() {
    int i;

    scanf("%d",&n);
    for (i=1;i<=n;i++) scanf("%d",&arr[i]);
    for (i=1;i<=n;i++) used[i] = 2;
    used[1] = 0;
    for (i=1;i<=n;i++) {
        int res = getv(i), l = ((i*2<=n)?arr[i*2]:INF), r = ((i*2+1<=n)?arr[i*2+1]:INF);
        int v = min({res,l,r});
        if (res==v) {
            used[i*2] = used[i*2+1] = 0;
            era(i,res);
        }
        else if (l==v) {used[i*2+1] = 0; used[i*2] = 1;}
        else used[i*2+1] = 1;
        brr[i] = v;
    }
    for (i=1;i<=n;i++) printf("%d ",brr[i]);
    printf("\n");

    return 0;
}

Compilation message (stderr)

swap.cpp: In function 'int main()':
swap.cpp:42:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
                   ^
swap.cpp:43:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (i=1;i<=n;i++) scanf("%d",&arr[i]);
                                           ^

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