fixed segment_tree_custom_merge_function

Author: dragonslayerx

src/segment_tree_custom_merge_function.cpp

@@ -1,7 +1,7 @@
 /**
- * Description: Segment Tree with custom merge function. 
- * Usage: construct O(N), query O(lg(N)), update O(lg(N)) 
- * Source: https://github.com/dragonslayerx 
+ * Description: Segment Tree with custom merge function.
+ * Usage: construct O(N), query O(lg(N)), update O(lg(N))
+ * Source: https://github.com/dragonslayerx
  */
 
 #include <iostream>
@@ -18,20 +18,23 @@ struct node {
  sum = prefix = suffix = 0;
  maxs = INF;
  }
- node(int a, int b, int c, int d) {
- assign(a, b, c, d);
+
+ node(int sum, int maxs, int prefix, int suffix) {
+ setNode(sum, maxs, prefix, suffix);
  }
- void assign(int a, int b, int c, int d)
- {
- sum = a, maxs = b, prefix = c, suffix = d;
+
+ void setNode(int sum, int maxs, int prefix, int suffix){
+ this->sum =sum;
+ this->maxs=maxs;
+ this->prefix=prefix;
+ this->suffix=suffix;
  }
 };
 
 int a[MAX];
 node st[4*MAX];
 
-node merge(node left, node right)
-{
+node merge(node left, node right){
  node t;
  t.prefix = max(left.prefix, left.sum+right.prefix);
  t.suffix = max(right.suffix, right.sum+left.suffix);
@@ -42,10 +45,9 @@ node merge(node left, node right)
  return t;
 }
 
-node construct(int n, int ll, int rl)
-{
+node construct(int n, int ll, int rl){
  if (ll == rl) {
- st[n].assign(a[ll], a[ll], a[ll], a[ll]);
+ st[n].setNode(a[ll], a[ll], a[ll], a[ll]);
  } else {
  node left = construct(2*n+1, ll, (ll+rl)/2);
  node right = construct(2*n+2, (ll+rl)/2+1, rl);
@@ -54,10 +56,9 @@ node construct(int n, int ll, int rl)
  return st[n];
 }
 
-node query(int n, int ll, int rl, int x, int y)
-{
+node query(int n, int ll, int rl, int x, int y){
  int mid = (ll+rl)/2;
- if (x == ll && y == rl) return st[n];
+ if (x==ll && y==rl) return st[n];
  else if (y <= mid) return query(2*n+1, ll, mid, x, y);
  else if (x > mid) return query(2*n+2, mid+1, rl, x, y);
  else {
@@ -67,16 +68,15 @@ node query(int n, int ll, int rl, int x, int y)
  }
 }
 
-node update(int n, int ll, int rl, int x, int color)
-{
- if (x < ll || x > rl) return st[n];
- if (x == ll && x == rl) {
- st[n].assign(//--Do everything Here--//);
+node update(int n, int ll, int rl, int p, int val){
+ if (p < ll || p > rl) return st[n];
+ if (p == ll && p == rl) {
+ st[n].setNode(val, val, val, val);
  return st[n];
  } else {
  int mid = (ll+rl)/2;
- node left = update(2*n+1, ll, (ll+rl)/2, x, color);
- node right = update(2*n+2, (ll+rl)/2+1, rl, x, color);
+ node left = update(2*n+1, ll, (ll+rl)/2, p, val);
+ node right = update(2*n+2, (ll+rl)/2+1, rl, p, val);
  st[n] = merge(left, right);
  }
  return st[n];
@@ -86,8 +86,7 @@ int main()
 {
  int n;
  scanf("%d", &n);
- for (int i = 0; i < n; i++)
- scanf("%d", a+i);
+ for (int i = 0; i < n; i++) scanf("%d", a+i);
  construct(0, 0, n-1);
  int q;
  scanf("%d", &q);

src/segment_tree_range_query_point_update.cpp

@@ -1,7 +1,7 @@
 /**
- * Description: Segment Tree Range query Point update. 
- * Usage: construct O(N), update O(lg(N)), query O(lg(N)) 
- * Source: https://github.com/dragonslayerx 
+ * Description: Segment Tree Range query Point update.
+ * Usage: construct O(N), update O(lg(N)), query O(lg(N))
+ * Source: https://github.com/dragonslayerx
  */
 
 #include <iostream>
@@ -17,8 +17,7 @@ long long a[MAX];
 int st[4*MAX];
 
 int construct (int node, int ll, int rl){
- if (ll == rl)
- st[node] = a[ll];
+ if (ll == rl) st[node] = a[ll];
  else {
  int left = construct(2*node+1, ll, (ll+rl)/2);
  int right = construct(2*node+2, (ll+rl)/2 + 1, rl);
@@ -35,8 +34,7 @@ int query(int node, int ll, int rl, int ql, int qr){
  return left + right;
 }
 
-int update(int node, int ll, int rl, int q, int val)
-{
+int update(int node, int ll, int rl, int q, int val){
  if (rl < q || ll > q) return st[node];
  if (q == ll && q == rl) st[node] = val;
  else {