From f7366924f269ad920144c944717a56b4a170c8bd Mon Sep 17 00:00:00 2001
From: Bruno Freitas Tissei <bft15@inf.ufpr.br>
Date: Fri, 15 Feb 2019 16:12:12 -0200
Subject: [PATCH] Fix lazy seg tree
Signed-off-by: Bruno Freitas Tissei <bft15@inf.ufpr.br>
---
algorithms/structure/lazy_segment_tree.cpp | 48 +++----
contests/Cadernaveis/URI1477.cpp | 148 +++++++++++++++++++++
2 files changed, 172 insertions(+), 24 deletions(-)
create mode 100644 contests/Cadernaveis/URI1477.cpp
diff --git a/algorithms/structure/lazy_segment_tree.cpp b/algorithms/structure/lazy_segment_tree.cpp
index 9f7552a..1fac1b0 100644
--- a/algorithms/structure/lazy_segment_tree.cpp
+++ b/algorithms/structure/lazy_segment_tree.cpp
@@ -10,9 +10,9 @@
int N, tree[4 * MAX], lazy[4 * MAX], v[MAX];
-// Build tree with elements from v
-void build_tree(int node = 1, int a = 0, int b = N) {
- if (a > b)
+// Builds tree with elements from v
+void build(int node = 1, int a = 0, int b = n) {
+ if (a > b)
return;
if (a == b) {
@@ -20,14 +20,16 @@ void build_tree(int node = 1, int a = 0, int b = N) {
return;
}
- build_tree(node * 2, a, (a + b) / 2);
- build_tree(node * 2 + 1, 1 + (a + b) / 2, b);
+ build(node * 2, a, (a + b) / 2);
+ build(node * 2 + 1, (a + b) / 2 + 1, b);
tree[node] = tree[node * 2] + tree[node * 2 + 1];
}
-void push(int node, int val) {
- tree[node] += value;
+// Propagates value to tree and through lazy tree
+void push(int node, int a, int b, int val) {
+ tree[node] += val;
+ // tree[node] += (b - a + 1) * val; (for Range Sum Query)
if (a != b) {
lazy[node * 2] += val;
@@ -38,39 +40,37 @@ void push(int node, int val) {
}
-// Update segment [i,j] by adding value val
-void update_tree(int i, int j, int val, int node = 1, int a = 0, int b = N) {
+// Updates segment [i,j] by adding value val
+void update(int i, int j, int val, int node = 1, int a = 0, int b = n) {
if (lazy[node] != 0)
- push(node, lazy[node]);
+ push(node, a, b, lazy[node]);
-
- if (a > b || a > j || b < i)
+ if (a > b or a > j or b < i)
return;
- if (a >= i && b <= j) {
- push(node, val);
+ if (a >= i and b <= j) {
+ push(node, a, b, val);
return;
}
- update_tree(i, j, node * 2, a, (a + b) / 2);
- update_tree(i, j, node * 2 + 1, 1 + (a + b) / 2, b);
+ update(i, j, val, node * 2, a, (a + b) / 2);
+ update(i, j, val, node * 2 + 1, (a + b) / 2 + 1, b);
tree[node] = tree[node * 2] + tree[node * 2 + 1];
}
-// Return sum of [i,j]
-int query_tree(int i, int j, int node = 1, int a = 0, int b = N) {
+// Returns sum of [i,j]
+int query(int i, int j, int node = 1, int a = 0, int b = n) {
if (a > b || a > j || b < i)
return 0;
- if (lazy[node] != 0) {
- push(node, val);
- }
+ if (lazy[node])
+ push(node, a, b, lazy[node]);
- if (a >= i && b <= j)
+ if (a >= i and b <= j)
return tree[node];
- int q1 = query_tree(i, j, node * 2, a, (a + b) / 2);
- int q2 = query_tree(i, j, node * 2 + 1, 1 + (a + b) / 2, b);
+ int q1 = query(i, j, node * 2, a, (a + b) / 2);
+ int q2 = query(i, j, node * 2 + 1, (a + b) / 2 + 1, b);
return q1 + q2;
}
diff --git a/contests/Cadernaveis/URI1477.cpp b/contests/Cadernaveis/URI1477.cpp
new file mode 100644
index 0000000..3790a06
--- /dev/null
+++ b/contests/Cadernaveis/URI1477.cpp
@@ -0,0 +1,148 @@
+#include <bits/stdc++.h>
+
+#define MAX 101010
+#define EPS 1e-6
+#define MOD 1000000007
+#define inf 0x3f3f3f3f
+#define llinf 0x3f3f3f3f3f3f3f3f
+
+#define fi first
+#define se second
+#define sz size()
+#define pb push_back
+#define ende '\n'
+
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define mset(x, y) memset(&x, (y), sizeof(x))
+
+using namespace std;
+
+typedef long long ll;
+typedef pair<int,int> ii;
+
+typedef struct elem {
+ int h, e, r;
+
+ elem() : h(0), e(0), r(0) {}
+ elem(int h, int e, int r) : h(h), e(e), r(r) {}
+
+ elem operator+(const elem &x) {
+ return elem(h + x.h, e + x.e, r + x.r);
+ }
+
+ void change(int n) {
+ int a = h, b = e, c = r;
+ if (n % 3 == 1) {
+ e = a;
+ r = b;
+ h = c;
+ } else if (n % 3 == 2) {
+ e = c;
+ r = a;
+ h = b;
+ }
+ }
+} elem;
+
+
+int n;
+elem v[MAX];
+elem tree[MAX * 4];
+int lazy[MAX * 4];
+
+void build(int node = 1, int a = 0, int b = n) {
+ if (a > b) return;
+
+ if (a == b) {
+ tree[node] = v[a];
+ return;
+ }
+
+ build(node * 2, a, (a + b) / 2);
+ build(node * 2 + 1, (a + b) / 2 + 1, b);
+ tree[node] = tree[node * 2] + tree[node * 2 + 1];
+}
+
+
+void push(int node, int a, int b, int val) {
+ tree[node].change(val);
+
+ if (a != b) {
+ lazy[node * 2] += val;
+ lazy[node * 2 + 1] += val;
+ }
+
+ lazy[node] = 0;
+}
+
+
+void update(int i, int j, int node = 1, int a = 0, int b = n) {
+ if (lazy[node] != 0)
+ push(node, a, b, lazy[node]);
+
+ if (a > b or a > j or b < i)
+ return;
+
+ if (a >= i and b <= j) {
+ push(node, a, b, 1);
+ return;
+ }
+
+ update(i, j, node * 2, a, (a + b) / 2);
+ update(i, j, node * 2 + 1, (a + b) / 2 + 1, b);
+ tree[node] = tree[node * 2] + tree[node * 2 + 1];
+}
+
+
+elem query(int i, int j, int node = 1, int a = 0, int b = n) {
+ if (a > b || a > j || b < i)
+ return elem();
+
+ if (lazy[node])
+ push(node, a, b, lazy[node]);
+
+ if (a >= i and b <= j)
+ return tree[node];
+
+ elem q1 = query(i, j, node * 2, a, (a + b) / 2);
+ elem q2 = query(i, j, node * 2 + 1, (a + b) / 2 + 1, b);
+ return q1 + q2;
+}
+
+
+int main() {
+ ios::sync_with_stdio(0);
+ cin.tie(0);
+
+ int m;
+ while (cin >> n >> m) {
+ for (int i = 0; i < MAX * 4; ++i) {
+ tree[i] = elem();
+ lazy[i] = 0;
+ }
+
+ for (int i = 0; i < n; ++i) {
+ v[i].h = 1;
+ v[i].e = v[i].r = 0;
+ }
+
+ build();
+
+ for (int i = 0; i < m; ++i) {
+ char op;
+ int a, b; cin >> op >> a >> b;
+
+ if (op == 'C') {
+ elem x = query(a - 1, b - 1);
+ cout << x.h << " " << x.e << " " << x.r << ende;
+ } else {
+ update(a - 1, b - 1);
+ }
+ }
+
+ cout << ende;
+ }
+
+ return 0;
+}
--
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