QOJ.ac

QOJ

ID	Problem	Submitter	Result	Time	Memory	Language	File size	Submit time	Judge time
#795678	#8720. BFS 序 0	Calculatelove	WA	107ms	52564kb	C++14	2.8kb	2024-11-30 23:05:44	2024-11-30 23:05:44

Judging History

你现在查看的是最新测评结果

[2024-11-30 23:05:44]
评测

测评结果：WA
用时：107ms
内存：52564kb

查看

[2024-11-30 23:05:44]
提交

answer

#include <bits/stdc++.h>

const int N = 500100;

int n, Q;

int dep[N];
int anc[19][N];

int lca(int x, int y) {
    if (dep[x] > dep[y]) std::swap(dep[x], dep[y]);
    for (int i = 18; i >= 0; i --)
        if (dep[x] <= dep[y] - (1 << i)) y = anc[i][y];
    if (x == y) return x;
    for (int i = 18; i >= 0; i --)
        if (anc[i][x] ^ anc[i][y]) x = anc[i][x], y = anc[i][y];
    return anc[0][x];
}

int jump(int x, int y) {
    for (int i = 18; i >= 0; i --)
        if (dep[anc[i][x]] > dep[y]) x = anc[i][x];
    return x;
}

int m, seq[N];

bool exist[N];
int crulen, cru[N];

bool insert(int x) {
    if (exist[x]) {
        return 0;
    } else {
        exist[x] = 1, cru[++ crulen] = x;
        return 1;
    }
}

int tot, head[N], ver[N * 2], Next[N * 2], deg[N];
void add_edge(int u, int v) {
    ver[++ tot] = v;    Next[tot] = head[u];    head[u] = tot;    deg[v] ++;
}

int main() {
    scanf("%d", &n);

    for (int i = 2; i <= n; i ++)
        scanf("%d", &anc[0][i]), dep[i] = dep[anc[0][i]] + 1;
    
    for (int j = 1; j <= 18; j ++)
        for (int i = 1; i <= n; i ++)
            anc[j][i] = anc[j - 1][anc[j - 1][i]];

    scanf("%d", &Q);

    while (Q --) {
        tot = 0;
        for (int i = 1; i <= crulen; i ++) exist[cru[i]] = 0, head[cru[i]] = 0, deg[cru[i]] = 0;
        crulen = 0;

        scanf("%d", &m);

        for (int i = 1; i <= m; i ++)
            scanf("%d", &seq[i]);
        
        bool flag = 1;

        for (int i = 1; i <= m; i ++)
            if (!insert(seq[i])) flag = 0;
        
        if (!flag) {
            puts("No");
            continue;
        }

        int d = dep[seq[1]];
        for (int i = 2; i <= m; i ++)
            if (d <= dep[seq[i]]) d = dep[seq[i]];
            else flag = 0;

        if (!flag) {
            puts("No");
            continue;
        }

        for (int st = 1, ed; st <= m; st = ed + 1) {
            ed = st;
            while (ed < m && dep[seq[ed + 1]] == dep[seq[ed]]) ed ++;

            for (int i = st; i < ed; i ++) {
                int x = seq[i], y = seq[i + 1], z = lca(x, y);
                int fx = jump(x, dep[x] - dep[z] - 1), fy = jump(y, dep[y] - dep[z] - 1);

                insert(fx), insert(fy);
                add_edge(fx, fy);
            }
        }

        std::queue<int> q;
        for (int i = 1; i <= crulen; i ++)
            if (deg[cru[i]] == 0) q.push(cru[i]);
        
        int t = 0;
        while (q.size()) {
            int u = q.front(); q.pop();
            t ++;

            for (int i = head[u]; i; i = Next[i]) {
                int v = ver[i];
                if (-- deg[v] == 0) q.push(v);
            }
        }

        puts(t == crulen ? "Yes" : "No");
    }

    return 0;
}

Source code, Language: C++14

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100

Accepted

time: 0ms

memory: 48696kb

input:

6
1 1 3 2 4
10
4 3 6 2 5
1 4
3 2 4 5
5 2 5 4 6 3
3 1 4 2
3 5 6 3
5 4 5 2 6 1
4 4 3 2 5
4 4 6 2 3
3 3 2 6

output:

No
Yes
Yes
No
No
No
No
No
No
Yes

result:

ok 10 token(s): yes count is 3, no count is 7

Test #2:

score: -100

Wrong Answer

time: 107ms

memory: 52564kb

input:

300000
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1...

output:

No
No
No
No
No
No
No
No
No
No
Yes
No
No
No
No
Yes
Yes
No
No
No
No
No
No
No
No
Yes
No
No
No
No
No
Yes
No
No
No
Yes
No
No
No
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
Yes
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No
No
No
Yes
No
No
No
No
No
No
No
Yes
No
No
No
Yes
No
No
No
No
No
No...

result:

wrong answer expected YES, found NO [2nd token]