feat: usaco

codeforces/1003/c.cc

@@ -76,13 +76,9 @@ void solve() {
 
   a[0] = min(a[0], x - a[0]);
   for (int i = 1; i < n; ++i) {
-    if (a[i] >= a[i - 1] && x - a[i] >= a[i - 1]) {
+    if (x - a[i] >= a[i - 1]) {
       a[i] = min(a[i], x - a[i]);
-    } else if (a[i] >= a[i - 1]) {
-      ;
-    } else if (x - a[i] >= a[i - 1]) {
-      a[i] = x - a[i];
-    } else {
+    } else if (a[i] < a[i - 1]) {
       prln("NO");
       return;
     }

codeforces/1020/f.cc

@@ -0,0 +1,93 @@
+#include <bits/stdc++.h>  // {{{
+
+// https://codeforces.com/blog/entry/96344
+
+#pragma GCC optimize("O2,unroll-loops")
+#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
+
+using namespace std;
+
+using i32 = int32_t;
+using u32 = uint32_t;
+using i64 = int64_t;
+using u64 = uint64_t;
+using d64 = double;
+using d128 = long double;
+template <typename T>
+using vec = std::vector<T>;
+template <typename T, size_t N>
+using arr = std::array<T, N>;
+template <typename T1, typename T2>
+using pai = std::pair<T1, T2>;
+
+template <typename T>
+constexpr T MIN = std::numeric_limits<T>::min();
+
+template <typename T>
+constexpr T MAX = std::numeric_limits<T>::max();
+
+template <typename T>
+[[nodiscard]] static T sc(auto&& x) {
+  return static_cast<T>(x);
+}
+
+template <typename T>
+[[nodiscard]] static T sz(auto&& x) {
+  return static_cast<T>(x.size());
+}
+
+static void NO() {
+  std::cout << "NO\n";
+}
+
+static void YES() {
+  std::cout << "YES\n";
+}
+
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+
+#ifdef LOCAL
+#define db(...) std::print(__VA_ARGS__)
+#define dbln(...) std::println(__VA_ARGS__)
+#else
+#define db(...)
+#define dbln(...)
+#endif
+//  }}}
+
+void solve() {
+  u32 n;
+  cin >> n;
+
+  string s;
+  cin >> s;
+
+  // NOTE: thought could loop thru the entire thing
+  // knew memory was O(n^2), but didn't actually say:
+  // ok what do i want to do - loop thru. this is impractical
+  string prev(n, '1');
+  // union_find<u64> uf;
+  for (u32 i = 0; i < n; ++i) {
+    if (i)
+      s[i] = ('0' + 1 - (s[i] - '0'));
+    s[i] = ('0' + 1 - (s[i] - '0'));
+    cout << "i: " << i << endl;
+    cout << s << endl;
+  }
+}
+
+int main() {  // {{{
+  cin.tie(nullptr)->sync_with_stdio(false);
+  cin.exceptions(cin.failbit);
+
+  int tc = 1;
+  cin >> tc;
+
+  for (int t = 0; t < tc; ++t) {
+    solve();
+  }
+
+  return 0;
+}
+// }}}

codeforces/1020/io/f.in

@@ -0,0 +1,13 @@
+6
+3
+000
+4
+0010
+7
+1011001
+4
+0001
+2
+11
+1
+0

codeforces/1020/io/f.out

@@ -0,0 +1,24 @@
+100
+010
+001
+1010
+0110
+0000
+0011
+0011001
+1111001
+1001001
+1010001
+1011101
+1011011
+1011000
+1001
+0101
+0011
+0000
+01
+10
+1
+
+[code]: 0
+[time]: 4.11367 ms