Updated libaries

Data Structures/fenwick_tree.cpp

@@ -1,8 +1,8 @@
-class fenwick_tree {
+template<typename T> class fenwick_tree {
-private: vector<int> FT;
+private: vector<T> FT;
 public:
 	fenwick_tree(int N) { FT.assign(N + 1, 0); }
-	void update(int x, int val) { for (; x < FT.size(); x += x & -x) FT[x] += val; }
+	void update(int x, T val) { if (x > 0) for (; x < FT.size(); x += x & -x) FT[x] += val; }
-	int query(int x) { int ret = 0; if (x > 0) for (; x > 0; x -= x & -x) ret += FT[x]; return ret; }
+	T query(int x) { T ret = 0; if (x > 0) for (; x > 0; x -= x & -x) ret += FT[x]; return ret; }
-	int query(int x, int y) { return query(y) - (x == 1 ? 0 : query(x - 1)); }
+	T query(int x, int y) { return query(y) - (x == 1 ? 0 : query(x - 1)); }
 };

Graph/lca.cpp

@@ -1,17 +1,17 @@
-int d[50005] = { 0 }, L[20][50005] = { 0 };
+int d[200005], L[200005][20];
-vector<int> G[50005];
+vi G[200005];
 
 void dfs(int u, int p) {
 	d[u] = d[p] + 1;
-	L[0][u] = p;
+	L[u][0] = p;
-	for (int i = 0; (1 << i) < N; i++) if (L[i][u]) L[i + 1][u] = L[i][L[i][u]];
+	for (int i = 0; i < 16 && L[u][i]; i++) L[u][i + 1] = L[L[u][i]][i];
-	for (int v : G[u]) if (v != p) dfs(v, u);
+	for (auto& v : G[u]) if (v != p) dfs(v, u);
 }
 
 int lca(int u, int v) {
 	if (d[u] > d[v]) swap(u, v);
-	for (int i = log2(N); i >= 0; i--) if (d[v] - (1 << i) >= d[u]) v = L[i][v];
+	for (int i = 16; i >= 0; i--) if (d[v] - (1 << i) >= d[u]) v = L[v][i];
 	if (u == v) return u;
-	for (int i = log2(N); i >= 0; i--) if (L[i][u] && L[i][u] != L[i][v]) u = L[i][u], v = L[i][v];
+	for (int i = 16; i >= 0; i--) if (L[u][i] && L[u][i] != L[v][i]) u = L[u][i], v = L[v][i];
-	return L[0][u];
+	return L[u][0];
 }

String/kmp.cpp

@@ -1,7 +1,3 @@
-#include <string>
-#include <vector>
-using namespace std;
-
 int KMP(string &S, string &T) {
 	// Generate KMP table
 	vector<int> F(T.length() + 1, 0);