feat(codeforces): 937 a-f

posts/algorithms/competitive-programming-log.html

@@ -24,6 +24,71 @@
           <h1 class="post-title">competitive programming log</h1>
         </header>
         <article class="post-article">
+          <h2>
+            <a href="https://codeforces.com/contest/2094" target="_blank"
+              >937 (div. 4)</a
+            >
+            <span class="post-meta">
+              <time datetime="2025-04-16">04/16/2025</time>
+            </span>
+          </h2>
+          <div>
+            ~1300 performance. Consistently finishing E, getting F occasionally.
+          </div>
+          <ol>
+            <li>
+              B: took me way too long because I just wanted to code. Wasted 5
+              minutes when I know better&mdash;patience and a formula got me
+              there in 30 seconds.
+            </li>
+            <blockquote>
+              Impatience is holding me back. Lack of discipline and focus is
+              holding me back. It doesn't just harm my <s>ranking</s>
+              problem-solving ability but it
+              <i>prevents me from improving</i>.
+            </blockquote>
+            <li>C: submitted without rigorously checking all edge cases.</li>
+            <li>
+              D: misunderstood the problem statement twice. Polya and Zeitz both
+              advise to fully understand exactly what the problem statement is
+              asking, whether through direct analysis or examples. Then, I
+              messed up the brute force. However, I did notice that raw
+              recursion would not TLE based on the fact that each number can be
+              divided in only a few ways.
+            </li>
+            <li>
+              E: I knew a number didn't have that many divisors but the
+              implementation took me too long.
+              <b
+                >Pay closer attention to the constraints and just solve the
+                problem.</b
+              >. Spend a bit more time on implementation,
+              <i>even if you know a way that works</i>. Here, I knew an approach
+              to code but it was easily error-prone.
+            </li>
+            <li>
+              Immediately came up with the idea but was unable to express it in
+              code. This means I did not fully understand the problem, namely
+              with some core mistakes:
+              <ol>
+                <li>The tree it not necessarily binary</li>
+                <li>
+                  C's cannot have children, so tracking depth/available nodes to
+                  fill per level is crucial
+                </li>
+                <li>
+                  Coming up with the expression \(a=c+1\) (and ensuring the
+                  input conforms to that) is a lot easier than cusotm coding
+                  logic to ensure levels are filled out properly. The core
+                  problem is that I lack the mathematical prowess to be certain
+                  of what exactly I need to check after I make that assertion
+                  and why. In this case, it means that the number of C's is
+                  appropriate, <i>so I never even need to check them</i>&mdash;I
+                  just need to make sure that the rest of the solution is valid.
+                </li>
+              </ol>
+            </li>
+          </ol>
           <h2>
             <a href="https://codeforces.com/contest/2094" target="_blank"
               >1017 (div. 4)</a
@@ -715,7 +780,8 @@
               </li>
             </ol>
           </div>
-          <h2>cses (range queries, sorting and searching)
+          <h2>
+            cses (range queries, sorting and searching)
             <span class="post-meta">
               <time datetime="2025-03-01">03/01/2025</time>
             </span>
@@ -833,7 +899,8 @@
               </li>
             </ol>
           </div>
-          <h2>sorting and searching
+          <h2>
+            sorting and searching
             <span class="post-meta">
               <time datetime="2025-02-24">02/24/2025</time>
             </span>
@@ -897,7 +964,8 @@
               </li>
             </ol>
           </div>
-          <h2>more cses
+          <h2>
+            more cses
             <span class="post-meta">
               <time datetime="2025-02-22">02/22/2025</time>
             </span>
@@ -931,7 +999,8 @@
               </li>
             </ol>
           </div>
-          <h2>cses
+          <h2>
+            cses
             <span class="post-meta">
               <time datetime="2025-02-21">02/21/2025</time>
             </span>
@@ -1157,7 +1226,8 @@
               </li>
             </ol>
           </div>
-          <h2>the beginning
+          <h2>
+            the beginning
             <span class="post-meta">
               <time datetime="2025-02-12">02/12/2025</time>
             </span>