update

Author: lrvideckis

library/data_structures_[l,r)/seg_tree_uncommon/min_left.hpp

@@ -5,5 +5,5 @@ int min_left(int l, int r, const auto& f) {
       r -= 1 << v, x = y;
     else l = r - (1 << v) + 1;
   }
-  return l;
+  return r;
 }

library/data_structures_[l,r]/seg_tree_uncommon/min_left.hpp

@@ -1,10 +1,11 @@
 int min_left(int l, int r, const auto& f) {
   if (T x = s[r + n]; f(x))
-    while (l < r) {
-      int u = r + n, v = __lg(min(u & -u, r - l));
+    for (r--; l <= r;) {
+      cout << "l,r:" << l << ' ' << r << endl; // 0 1
+      int u = r + 1 + n, v = __lg(min(u & -u, r - l + 1));
       if (T y = op(s[(u - 1) >> v], x); f(y))
         r -= 1 << v, x = y;
       else l = r - (1 << v) + 1;
     }
-  return l;
+  return r;
 }

tests/library_checker_aizu_tests/data_structures/simple_tree_inc_walk.test.cpp

@@ -10,7 +10,7 @@ int main() {
   cin >> s;
   vector<int> init(n);
   for (int i = 0; i < n; i++) init[i] = s[i] - '0';
-  tree st(init, plus<int>{});
+  tree st(init, ranges::max);
   while (q--) {
     int type, k;
     cin >> type >> k;
@@ -21,21 +21,16 @@ int main() {
     } else if (type == 2) {
       cout << st.query(k, k) << '\n';
     } else if (type == 3) {
-      // returns first element in [k,n-1] such that sum > 0
+      // returns first element in [k,n-1] such that mx > 0
       int idx = st.max_right(k, n - 1,
-        [&](int sum) { return sum == 0; });
+        [&](int mx) { return mx == 0; });
       if (idx == n) idx = -1;
       cout << idx << '\n';
     } else {
       assert(type == 4);
-      int total = st.query(0, k);
-      if (total == 0) {
-        cout << -1 << '\n';
-      } else {
-        cout << st.max_right(0, k, [&](int sum) {
-          return sum < total;
-        }) << '\n';
-      }
+      cout << st.min_left(0, k, [&](int mx) {
+        return mx == 0;
+      }) << '\n';
     }
   }
   return 0;

tests/library_checker_aizu_tests/data_structures/simple_tree_walk.test.cpp

@@ -6,7 +6,7 @@ int main() {
   cin.tie(0)->sync_with_stdio(0);
   int n, q;
   cin >> n >> q;
-  tree st(n, 0, plus<int>{});
+  tree st(n, INT_MIN, ranges::max);
   string s;
   cin >> s;
   for (int i = 0; i < n; i++) st.update(i, s[i] - '0');
@@ -20,21 +20,16 @@ int main() {
     } else if (type == 2) {
       cout << st.query(k, k + 1) << '\n';
     } else if (type == 3) {
-      // returns first element in [k,n) such that sum > 0
+      // returns first element in [k,n) such that mx > 0
       int idx = st.max_right(k, n,
-        [&](int sum) { return sum == 0; });
+        [&](int mx) { return mx == 0; });
       if (idx == n) idx = -1;
       cout << idx << '\n';
     } else {
       assert(type == 4);
-      int total = st.query(0, k + 1);
-      if (total == 0) {
-        cout << -1 << '\n';
-      } else {
-        cout << st.max_right(0, k + 1, [&](int sum) {
-          return sum < total;
-        }) << '\n';
-      }
+      cout << st.min_left(0, k + 1,
+                [&](int mx) { return mx == 0; }) -
+          1 << '\n';
     }
   }
   return 0;