Submission #37062

#	Time	Username	Problem	Language	Result	Execution time	Memory
37062		DoanPhuDuc	Chase (CEOI17_chase)	C++98	100 / 100	919 ms	446516 KiB

chase

#include <bits/stdc++.h>

#define FOR(x, a, b) for (int x = a; x <= b; ++x)
#define FOD(x, a, b) for (int x = a; x >= b; --x)
#define REP(x, a, b) for (int x = a; x < b; ++x)
#define DEBUG(X) { cout << #X << " = " << X << endl; }
#define PR(A, n) { cout << #A << " = "; FOR(_, 1, n) cout << A[_] << " "; cout << endl; }
#define PR0(A, n)  { cout << #A << " = "; REP(_, 0, n) cout << A[_] << " "; cout << endl; }

using namespace std;

typedef long long LL;
typedef pair <int, int> II;

const int N = 1e5 + 10;
const int A = 1e2 + 10;
const LL INFL = (LL)1e18;

int n, m;
int a[N], p[N], b[N], R[N];

LL S[N], C1[N][2], C2[N][2];
LL f[N][A][2], g[N][A][2], h[N][A];

vector <int> adj[N];

void DFS(int u, int par = -1) {
    S[u] = a[u];
    REP(k, 0, adj[u].size()) {
        int v = adj[u][k]; if (v == par) continue;
        S[u] += a[v];
        p[v] = u;
        DFS(v, u);
    }
}

void DP(int u, int par = -1) {
    f[u][0][0] = 0;
    f[u][1][1] = S[u] - a[u];
    g[u][0][0] = 0;
    g[u][1][1] = S[u] - a[u];
    REP(k, 0, adj[u].size()) {
        int v = adj[u][k]; if (v == par) continue;
        DP(v, u);
        FOR(i, 1, m) {
            f[u][i][0] = max(f[u][i][0], f[v][i][1] + a[u]);
            f[u][i][0] = max(f[u][i][0], f[v][i][0]);

            f[u][i][1] = max(f[u][i][1], f[v][i - 1][1] + S[u] - a[v]);
            f[u][i][1] = max(f[u][i][1], f[v][i - 1][0] + S[u] - a[v] - a[u]);

            FOR(j, 0, 1)
                g[u][i][0] = max(g[u][i][0], g[v][i][j]);
            FOR(j, 0, 1)
                g[u][i][1] = max(g[u][i][1], g[v][i - 1][j] + S[u] - a[u]);
        }
    }
}

int main() {
    #ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif // LOCAL
    scanf("%d%d", &n, &m);
    FOR(i, 1, n) scanf("%d", &a[i]);
   /* int m = n;
    FOR(i, 1, n) R[i] = a[i];
    sort(R + 1, R + m + 1); m = unique(R + 1, R + m + 1) - R - 1;
    FOR(i, 1, n) b[i] = lower_bound(R + 1, R + m+ 1, a[i]) - R;
    PR(b, n);*/
    FOR(i, 1, n - 1) {
        int u, v; scanf("%d%d", &u, &v);
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
   // FOR(i, 1, n) cout << a[i] << endl;
   //cout << endl;
    int Root = 1;
    FOR(u, 1, n)
        FOR(i, 0, m)
            FOR(k, 0, 1) f[u][i][k] = g[u][i][k] = -INFL;
    DFS(Root);
    DP(Root);
    FOR(u, 1, n) {
        FOR(i, 1, m)
            FOR(k, 0, 1) {
                f[u][i][k] = max(f[u][i][k], f[u][i - 1][k]);
                g[u][i][k] = max(g[u][i][k], g[u][i - 1][k]);
            }
    }
    FOR(u, 1, n)
        FOR(i, 1, m)
            FOR(k, 0, 1) h[u][i] = max(h[u][i], g[u][i][k]);
    LL ans = -INFL;
    FOR(w, 1, n) {
        FOR(i, 0, m) ans = max(ans, max(f[w][i][0], f[w][i][1] + a[p[w]]));
        FOR(i, 0, m) ans = max(ans, max(g[w][i][0], g[w][i][1] + a[p[w]]));
        FOR(i, 1, m)
            FOR(k, 0, 1) C1[i][k] = -INFL, C2[i][k] = -INFL;
        REP(k, 0, adj[w].size()) {
            int v = adj[w][k]; if (v == p[w]) continue;
            // u has drop
            FOR(i, 1, m - 1) {
                ans = max(ans, S[w] - a[w] + C1[i][1] + h[v][m - i - 1] + a[p[w]]);
                ans = max(ans, S[w] - a[w] + C1[i][0] + h[v][m - i - 1] + a[p[w]]);
            }
            // u has not drop
            FOR(i, 1, m) {
                ans = max(ans, C2[i][1] + h[v][m - i]);
                ans = max(ans, C2[i][0] + h[v][m - i]);
            }
            FOR(i, 1, m)
                FOR(j, 0, 1)
                    C1[i][j] = max(C1[i][j], f[v][i][j] + (j == 1 ? a[p[v]] : 0) - a[v]);
            FOR(i, 1, m)
                FOR(j, 0, 1)
                    C2[i][j] = max(C2[i][j], f[v][i][j] + (j == 1 ? a[p[v]] : 0));
        }
        reverse(adj[w].begin(), adj[w].end());
        FOR(i, 1, m)
            FOR(k, 0, 1) C1[i][k] = -INFL, C2[i][k] = -INFL;
        REP(k, 0, adj[w].size()) {
            int v = adj[w][k]; if (v == p[w]) continue;
            // u has drop
            FOR(i, 1, m - 1) {
                ans = max(ans, S[w] - a[w] + C1[i][1] + h[v][m - i - 1] + a[p[w]]);
                ans = max(ans, S[w] - a[w] + C1[i][0] + h[v][m - i - 1] + a[p[w]]);
            }
            // u has not drop
            FOR(i, 1, m) {
                ans = max(ans, C2[i][1] + h[v][m - i]);
                ans = max(ans, C2[i][0] + h[v][m - i]);
            }
            FOR(i, 1, m)
                FOR(j, 0, 1)
                    C1[i][j] = max(C1[i][j], f[v][i][j] + (j == 1 ? a[p[v]] : 0) - a[v]);
            FOR(i, 1, m)
                FOR(j, 0, 1)
                    C2[i][j] = max(C2[i][j], f[v][i][j] + (j == 1 ? a[p[v]] : 0));
        }
    }
    printf("%lld", ans);
    return 0;
}

Compilation message (stderr)

chase.cpp: In function 'void DFS(int, int)':
chase.cpp:5:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define REP(x, a, b) for (int x = a; x < b; ++x)
                                        ^
chase.cpp:29:5: note: in expansion of macro 'REP'
     REP(k, 0, adj[u].size()) {
     ^
chase.cpp: In function 'void DP(int, int)':
chase.cpp:5:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define REP(x, a, b) for (int x = a; x < b; ++x)
                                        ^
chase.cpp:42:5: note: in expansion of macro 'REP'
     REP(k, 0, adj[u].size()) {
     ^
chase.cpp: In function 'int main()':
chase.cpp:5:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define REP(x, a, b) for (int x = a; x < b; ++x)
                                        ^
chase.cpp:101:9: note: in expansion of macro 'REP'
         REP(k, 0, adj[w].size()) {
         ^
chase.cpp:5:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define REP(x, a, b) for (int x = a; x < b; ++x)
                                        ^
chase.cpp:123:9: note: in expansion of macro 'REP'
         REP(k, 0, adj[w].size()) {
         ^
chase.cpp:65:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
                          ^
chase.cpp:66:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     FOR(i, 1, n) scanf("%d", &a[i]);
                                    ^
chase.cpp:73:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         int u, v; scanf("%d%d", &u, &v);
                                        ^

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 30 / 30