제출 #211873

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
211873		jk89	건물 4 (JOI20_building4)	C++14	0 / 100	5 ms	256 KiB

building4

#include <cstdio>
#include <algorithm>
#include <vector>

using namespace std;

#define f first
#define s second

const int MAXN = 1e6 + 3;
const int INF = 1e9 + 3;

int t[MAXN][2];
pair<int, int> dp[MAXN][2];
bool ans[MAXN];
int a = 0, b = 0, akt;

bool possible(int wym, int ind) {
    if (dp[ind][wym].f == INF)
        return false;
    if (t[ind][wym] > t[ind + 1][akt])
        return false;
    return b - a >= dp[ind][wym].f && b - a <= dp[ind][wym].s;
}

void check(int wym, int ind) {
    if (abs(dp[ind][wym].f - INF) == 1)
        dp[ind][wym].f = INF;
    if (abs(dp[ind][wym].s + INF) == 1)
        dp[ind][wym].s = -INF;
}

int main() {
    int n;
    scanf("%d", &n);
    n *= 2;
    for (int i = 0; i < 2; i++) {
        for (int j = 1; j <= n; j++)
            scanf("%d", &t[j][i]);
    }
    for (int i = 1; i <= n; i++) {
        dp[i][0] = dp[i][1] = {INF, -INF};
        if (t[i - 1][0] <= t[i][0]) {
            dp[i][0] = dp[i - 1][0];
            dp[i][0].f++;
            dp[i][0].s++;
        }
        if (t[i - 1][1] <= t[i][0]) {
            dp[i][0].f = min(dp[i][0].f, dp[i - 1][1].f + 1);
            dp[i][0].s = max(dp[i][0].s, dp[i - 1][1].s + 1);
        }

        if (t[i - 1][0] <= t[i][1]) {
            dp[i][1] = dp[i - 1][0];
            dp[i][1].f--;
            dp[i][1].s--;
        }
        if (t[i - 1][1] <= t[i][1]) {
            dp[i][1].f = min(dp[i][1].f, dp[i - 1][1].f - 1);
            dp[i][1].s = max(dp[i][1].s, dp[i - 1][1].s - 1);
        }

        check(i, 0);
        check(i, 1);
    }
    if (dp[n][0].f <= 0 && dp[n][0].s >= 0) {
        a++;
        akt = 0;
    }
    else if (dp[n][1].f <= 0 && dp[n][1].s >= 0) {
        b++;
        akt = 1;
        ans[n] = true;
    }
    else {
        printf("-1");
        return 0;
    }
    for (int i = n; i > 1; i--) {
        if (possible(0, i - 1)) {
            a++;
            akt = 0;
        }
        else {
            b++;
            akt = 1;
            ans[i - 1] = true;
        }
    }
    for (int i = 1; i <= n; i++)
        printf(ans[i] ? "B" : "A");
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

building4.cpp: In function 'int main()':
building4.cpp:35:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
building4.cpp:39:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", &t[j][i]);
             ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 0 / 11
• Subtask 2: 0 / 89