oj.uz

Submission #56536

# Submission time Handle Problem Language Result Execution time Memory
56536 2018-07-11T15:11:12 Z aquablitz11 Islands (IOI08_islands) C++14
80 / 100
 582 ms 132096 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

const int N = 1000010; 
const ll INF = 1e18;
ll par[N], len[N], deg[N], h1[N], h2[N], dp[N];

int main()
{
    int n;
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i) {
        int v, w;
        scanf("%d%d", &v, &w);
        par[i] = v;
        len[i] = w;
        ++deg[v];
    }
    queue<int> Q;
    for (int i = 1; i <= n; ++i) {
        if (deg[i] == 0)
            Q.push(i);
    }
    while (!Q.empty()) {
        int u = Q.front(); Q.pop();
        int v = par[u];
        ll w = len[u];
        if (h1[u]+w > h1[v]) {
            h2[v] = h1[v];
            h1[v] = h1[u]+w;
        } else if (h1[u]+w > h2[v]) {
            h2[v] = h1[u]+w;
        }
        dp[u] = max(dp[u], h1[u]+h2[u]);
        dp[v] = max(dp[v], dp[u]);
        if (--deg[v] == 0)
            Q.push(v);
    }
    ll ttans = 0;
    for (int i = 1; i <= n; ++i) {
        if (deg[i] == 1) {
            int u = i;
            vector<int> cyc;
            ll ttd = 0;
            do {
                cyc.push_back(u);
                deg[u] = 0;
                ttd += len[u];
                u = par[u];
            } while (u != i);

            ll mxm = -INF, mxp = -INF, d = 0, ans = -INF;
            for (auto u : cyc) {
                dp[u] = max(dp[u], h1[u]+h2[u]);
                ans = max(ans, dp[u]);
                ans = max(ans, h1[u]+d+mxm);
                ans = max(ans, h1[u]-d+ttd+mxp);
                mxm = max(mxm, h1[u]-d);
                mxp = max(mxp, h1[u]+d);
                d += len[u];
            }
            ttans += ans;
        }
    }
    printf("%lld\n", ttans);

    return 0;
}

Compilation message

islands.cpp: In function 'int main()':
islands.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
islands.cpp:15:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &v, &w);
         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 3 ms 488 KB Output is correct
3 Correct 3 ms 488 KB Output is correct
4 Correct 2 ms 656 KB Output is correct
5 Correct 2 ms 660 KB Output is correct
6 Correct 2 ms 724 KB Output is correct
7 Correct 2 ms 792 KB Output is correct
8 Correct 2 ms 792 KB Output is correct
9 Correct 2 ms 792 KB Output is correct
10 Correct 2 ms 796 KB Output is correct
11 Correct 2 ms 796 KB Output is correct

Subtask #2
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 796 KB Output is correct
2 Correct 4 ms 796 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 940 KB Output is correct
2 Correct 4 ms 1096 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 1796 KB Output is correct
2 Correct 18 ms 3288 KB Output is correct
3 Correct 12 ms 3288 KB Output is correct
4 Correct 9 ms 3288 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 5160 KB Output is correct
2 Correct 39 ms 8348 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 100 ms 16036 KB Output is correct
2 Correct 76 ms 17952 KB Output is correct
3 Correct 96 ms 25464 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 188 ms 35552 KB Output is correct
2 Correct 192 ms 48788 KB Output is correct
3 Correct 163 ms 50960 KB Output is correct
4 Correct 238 ms 71060 KB Output is correct

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 362 ms 81340 KB Output is correct
2 Correct 582 ms 108380 KB Output is correct
3 Correct 324 ms 117484 KB Output is correct
4 Runtime error 405 ms 132096 KB Memory limit exceeded 132096 {'time-wall': '0.472', 'max-rss': '51268', 'csw-forced': '107', 'cg-mem': '132096', 'time': '0.405', 'csw-voluntary': '8'} 131072
5 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 398 ms 132096 KB Memory limit exceeded 132096 {'time-wall': '0.445', 'max-rss': '48512', 'csw-forced': '181', 'cg-mem': '132096', 'time': '0.398', 'csw-voluntary': '5'} 131072
2 Halted 0 ms 0 KB -