Submission #65800

#TimeUsernameProblemLanguageResultExecution timeMemory
65800kingpig9Birthday gift (IZhO18_treearray)C++11
56 / 100
4021 ms51888 KiB
#include <bits/stdc++.h> using namespace std; typedef long long ll; typedef pair<int, int> pii; typedef pair<ll, ll> pll; const int MAXN = 1 << 18, MAXLG = 18; //#define debug(...) fprintf(stderr, __VA_ARGS__) #define debug(...) #define fi first #define se second #define all(v) (v).begin(), (v).end() #define fillchar(a, s) memset((a), (s), sizeof(a)) int N, M, Q; vector<int> adj[MAXN]; int par[MAXN][MAXLG], depth[MAXN]; int ent[MAXN], exi[MAXN]; int A[MAXN]; int getpar (int x, int d) { for (int i = 0; d; d >>= 1, i++) { if (d & 1) { x = par[x][i]; } } return x; } int lca (int x, int y) { if (x == 0 || y == 0) { return 0; } if (x == -1) { return y; } if (y == -1) { return x; } debug("LCA %d %d: ", x, y); if (depth[x] < depth[y]) { swap(x, y); } x = getpar(x, depth[x] - depth[y]); debug("so %d %d\n", x, y); if (x == y) { debug("DR %d\n", x); return x; } for (int i = MAXLG - 1; i >= 0; i--) { if (par[x][i] != par[y][i]) { x = par[x][i]; y = par[y][i]; } } debug("PR %d\n", par[x][0]); return par[x][0]; } bool isanc (int x, int y) { return ent[x] <= ent[y] && exi[y] <= exi[x]; } void dfs (int x) { static int cur = 0; ent[x] = cur++; for (int y : adj[x]) { adj[y].erase(find(all(adj[y]), x)); par[y][0] = x; for (int i = 1; i < MAXLG; i++) { par[y][i] = par[par[y][i - 1]][i - 1]; } depth[y] = depth[x] + 1; debug("depth[%d] = %d\n", y, depth[y]); dfs(y); } exi[x] = cur; } struct segtree { int tree[2 * MAXN]; void merge (int x) { tree[x] = lca(tree[2 * x], tree[2 * x + 1]); } void update (int x, int v) { tree[x += MAXN] = v; while (x >>= 1) { merge(x); } } int query (int a, int b, int cur = 1, int lt = 0, int rt = MAXN) { if (rt <= a || b <= lt) { debug("ha -1\n"); return -1; } if (a <= lt && rt <= b) { debug("tr %d\n", tree[cur]); return tree[cur]; } int mid = (lt + rt) / 2; return lca(query(a, b, 2 * cur, lt, mid), query(a, b, 2 * cur + 1, mid, rt)); } } seg; void init_segtree() { fillchar(seg.tree, -1); for (int i = 1; i <= M; i++) { scanf("%d", &A[i]); seg.tree[i + MAXN] = A[i]; } for (int i = MAXN - 1; i; i--) { seg.merge(i); } } pii solve (int lt, int rt, int v) { for (int i = lt, j = lt - 1; i <= rt; i++) { debug("A[%d] = %d\n", i, A[i]); if (!isanc(v, A[i])) { debug("ibobbob\n"); continue; } j = max(j, i); int c = seg.query(i, j + 1); debug("yeequery %d %d = %d\n", i, j, c); if (c == v) { return pii(i, j); } if (isanc(c, v)) { continue; } debug("i=%d,j=%d,c=%d.\n",i,j,c); while (j < rt) { j++; c = lca(c, A[j]); debug("i = %d, j = %d, c = %d\n", i, j, c); if (c == v) { return pii(i, j); } if (isanc(c, v)) { assert(c != v); break; } } } return pii(-1, -1); } int main() { scanf("%d %d %d", &N, &M, &Q); for (int i = 1; i < N; i++) { int x, y; scanf("%d %d", &x, &y); adj[x].push_back(y); adj[y].push_back(x); } dfs(1); init_segtree(); //and now...queries for (int qi = 1; qi <= Q; qi++) { int qt, v; scanf("%d", &qt); if (qt == 1) { int pos; scanf("%d %d", &pos, &v); A[pos] = v; seg.update(pos, v); } else { int lt, rt; scanf("%d %d %d", &lt, &rt, &v); pii ans = solve(lt, rt, v); if (ans != pii(-1, -1)) { debug("WHAT %d %d\n", lt, rt); debug("QU %d %d = %d\n", ans.fi, ans.se, seg.query(ans.fi, ans.se + 1)); assert(seg.query(ans.fi, ans.se + 1) == v); } printf("%d %d\n", ans.fi, ans.se); } } }

Compilation message (stderr)

treearray.cpp: In function 'void init_segtree()':
treearray.cpp:118:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &A[i]);
   ~~~~~^~~~~~~~~~~~~
treearray.cpp: In function 'int main()':
treearray.cpp:164:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d", &N, &M, &Q);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:167:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &x, &y);
   ~~~~~^~~~~~~~~~~~~~~~~
treearray.cpp:178:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &qt);
   ~~~~~^~~~~~~~~~~
treearray.cpp:181:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d", &pos, &v);
    ~~~~~^~~~~~~~~~~~~~~~~~~
treearray.cpp:186:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d %d", &lt, &rt, &v);
    ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
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