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Submission #88714

# Submission time Handle Problem Language Result Execution time Memory
88714 2018-12-07T18:23:26 Z popovicirobert Pipes (BOI13_pipes) C++14
70 / 100
 1000 ms 22444 KB 
#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
// 217
// 44

using namespace std;

const int MAXM = (int) 5e5;
const int MAXN = (int) 1e5;

vector < pair <int, int> > g[MAXN + 1];
int even[MAXN + 1], father[MAXN + 1], n;
bool vis[MAXN + 1];

void dfs(int nod) {
    vis[nod] = 1;
    for(auto it : g[nod]) {
        if(vis[it.first] == 0) {
            even[it.first] = (even[nod] ^ 1);
            father[it.first] = nod;
            dfs(it.first);
        }
    }
}

inline void detect_cycle(bool &cycle) {
    memset(even, -1, sizeof(even));
    even[1] = 0;
    dfs(1);
    int cnt = 0;
    for(int i = 1; i <= n; i++) {
        for(auto it : g[i]) {
            if(even[i] != even[it.first] && !(father[it.first] == i || father[i] == it.first)) {
                cout << 0;
                exit(0);
            }
            if(even[i] == even[it.first]) {
                cnt++;
            }
        }
    }
    cnt /= 2;
    if(cnt > 1) {
        cout << 0;
        exit(0);
    }
    if(cnt) {
        cycle = 1;
    }
}

ll c[MAXN + 1];
ll sol[MAXM + 1];

int deg[MAXN + 1];

inline void check() {
    for(int i = 1; i <= n; i++) {
        if(c[i] != 0) {
            while(1) {

            }
            cout << 0;
            exit(0);
        }
    }
}

inline void solve_tree(bool cycle) {
    int i;
    memset(vis, 0, sizeof(vis));
    queue <int> Q;
    for(i = 1; i <= n; i++) {
        if(g[i].size() == 1) {
            Q.push(i);
            vis[i] = 1;
        }
    }
    while(Q.size()) {
        int nod = Q.front();
        Q.pop();
        for(auto it : g[nod]) {
            if(vis[it.first] == 0) {
                deg[it.first]++;
                sol[it.second] = c[nod];
                c[it.first] -= c[nod];
                c[nod] = 0;
                if(deg[it.first] + 1 == g[it.first].size()) {
                    vis[it.first] = 1;
                    Q.push(it.first);
                }
            }
        }
    }
    if(cycle == 0) {
        check();
    }
}

void dfs1(int nod, vector < pair <int, int> > &nodes, int par, int root) {
    vis[nod] = 1;
    for(auto it : g[nod]) {
        if(it.first == par) {
            continue;
        }
        if(vis[it.first] == 0) {
            nodes.push_back({nod, it.second});
            dfs1(it.first, nodes, nod, root);
        }
        else if(it.first == root) {
            nodes.push_back({nod, it.second});
        }
    }
}

inline void solve_cycle(bool cycle) {
    if(cycle == 0) {
        return ;
    }
    int i, nod;
    for(i = 1; i <= n; i++) {
        if(vis[i] == 0) {
            nod = i;
            break;
        }
    }
    vector < pair <int, int> > nodes;
    dfs1(nod, nodes, 0, nod);
    int sz = nodes.size();
    ll tot = 0;
    for(auto it : nodes) {
        tot += c[it.first];
    }
    tot /= 2;
    ll sum = 0;
    for(i = 0; i + 1 < sz; i += 2) {
        sum += c[nodes[i].first];
    }
    sol[nodes[sz - 2].second] = tot - sum;
    c[nodes[sz - 2].first] -= tot - sum;
    for(i = sz - 3; i >= 0; i--) {
        sol[nodes[i].second] = c[nodes[i + 1].first];
        c[nodes[i].first] -= sol[nodes[i].second];
    }
    sum = 0;
    for(auto it : nodes) {
        sum += sol[it.second];
    }
    sol[nodes.back().second] = tot - sum;
}

int main() {
    //ifstream cin("A.in");
    //ofstream cout("A.out");
    int i, m;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    cin >> n >> m;
    for(i = 1; i <= n; i++) {
        cin >> c[i];
        c[i] *= 2LL;
    }
    for(i = 1; i <= m; i++) {
        int x, y;
        cin >> x >> y;
        g[x].push_back({y, i});
        g[y].push_back({x, i});
    }
    bool cycle = 0;
    detect_cycle(cycle);
    solve_tree(cycle);
    solve_cycle(cycle);
    for(i = 1; i <= m; i++) {
        cout << sol[i] << "\n";
    }
    //cin.close();
    //cout.close();
    return 0;
}

Compilation message

pipes.cpp: In function 'void solve_tree(bool)':
pipes.cpp:90:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                 if(deg[it.first] + 1 == g[it.first].size()) {
                    ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
pipes.cpp: In function 'void solve_cycle(bool)':
pipes.cpp:130:9: warning: 'nod' may be used uninitialized in this function [-Wmaybe-uninitialized]
     dfs1(nod, nodes, 0, nod);
     ~~~~^~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 30.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1073 ms 3192 KB Time limit exceeded
2 Execution timed out 1057 ms 3316 KB Time limit exceeded
3 Execution timed out 1062 ms 3384 KB Time limit exceeded
4 Execution timed out 1059 ms 9544 KB Time limit exceeded
5 Execution timed out 1069 ms 9544 KB Time limit exceeded
6 Execution timed out 1084 ms 9544 KB Time limit exceeded
7 Execution timed out 1087 ms 9544 KB Time limit exceeded
8 Execution timed out 1072 ms 9544 KB Time limit exceeded
9 Execution timed out 1082 ms 9544 KB Time limit exceeded
10 Execution timed out 1066 ms 9544 KB Time limit exceeded
11 Execution timed out 1082 ms 9544 KB Time limit exceeded
12 Execution timed out 1083 ms 9544 KB Time limit exceeded
13 Execution timed out 1089 ms 9544 KB Time limit exceeded
14 Execution timed out 1086 ms 9544 KB Time limit exceeded
15 Execution timed out 1085 ms 9824 KB Time limit exceeded
16 Execution timed out 1088 ms 9824 KB Time limit exceeded
17 Execution timed out 1084 ms 9824 KB Time limit exceeded
18 Execution timed out 1086 ms 9824 KB Time limit exceeded
19 Execution timed out 1077 ms 11232 KB Time limit exceeded
20 Execution timed out 1090 ms 11232 KB Time limit exceeded
21 Execution timed out 1079 ms 11232 KB Time limit exceeded
22 Execution timed out 1085 ms 11232 KB Time limit exceeded
23 Execution timed out 1094 ms 11232 KB Time limit exceeded
24 Execution timed out 1091 ms 11232 KB Time limit exceeded
25 Execution timed out 1089 ms 11232 KB Time limit exceeded

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 11232 KB Output is correct
2 Correct 5 ms 11232 KB Output is correct
3 Correct 68 ms 11232 KB Output is correct
4 Correct 83 ms 11408 KB Output is correct
5 Correct 75 ms 11408 KB Output is correct
6 Correct 282 ms 22396 KB Output is correct
7 Correct 4 ms 22396 KB Output is correct
8 Correct 4 ms 22396 KB Output is correct
9 Correct 4 ms 22396 KB Output is correct
10 Correct 4 ms 22396 KB Output is correct
11 Correct 5 ms 22396 KB Output is correct
12 Correct 4 ms 22396 KB Output is correct
13 Correct 4 ms 22396 KB Output is correct
14 Correct 5 ms 22396 KB Output is correct
15 Correct 5 ms 22396 KB Output is correct
16 Correct 9 ms 22396 KB Output is correct
17 Correct 5 ms 22396 KB Output is correct
18 Correct 5 ms 22396 KB Output is correct
19 Correct 5 ms 22396 KB Output is correct
20 Correct 5 ms 22396 KB Output is correct
21 Correct 6 ms 22396 KB Output is correct
22 Correct 5 ms 22396 KB Output is correct
23 Correct 86 ms 22396 KB Output is correct
24 Correct 122 ms 22396 KB Output is correct
25 Correct 80 ms 22396 KB Output is correct
26 Correct 89 ms 22396 KB Output is correct
27 Correct 90 ms 22396 KB Output is correct
28 Correct 95 ms 22396 KB Output is correct
29 Correct 242 ms 22396 KB Output is correct
30 Correct 136 ms 22396 KB Output is correct
31 Correct 115 ms 22396 KB Output is correct
32 Correct 95 ms 22396 KB Output is correct
33 Correct 74 ms 22396 KB Output is correct
34 Correct 80 ms 22396 KB Output is correct
35 Correct 92 ms 22396 KB Output is correct
36 Correct 80 ms 22396 KB Output is correct
37 Correct 302 ms 22444 KB Output is correct
38 Correct 107 ms 22444 KB Output is correct
39 Correct 96 ms 22444 KB Output is correct
40 Correct 101 ms 22444 KB Output is correct
41 Correct 72 ms 22444 KB Output is correct
42 Correct 79 ms 22444 KB Output is correct
43 Correct 70 ms 22444 KB Output is correct
44 Correct 76 ms 22444 KB Output is correct
45 Correct 212 ms 22444 KB Output is correct
46 Correct 100 ms 22444 KB Output is correct
47 Correct 102 ms 22444 KB Output is correct
48 Correct 104 ms 22444 KB Output is correct
49 Correct 59 ms 22444 KB Output is correct
50 Correct 73 ms 22444 KB Output is correct
51 Correct 72 ms 22444 KB Output is correct
52 Correct 74 ms 22444 KB Output is correct
53 Correct 213 ms 22444 KB Output is correct
54 Correct 126 ms 22444 KB Output is correct