From 692189eefb2f9bae62e23ca8d7a1553e447af3da Mon Sep 17 00:00:00 2001
From: Andrei Ovcharenko <a@krot.name>
Date: Fri, 31 Jul 2026 17:43:36 +0300
Subject: [PATCH] Validate sprint7 solver input bounds

---
 .../java/algorithms/sprint7/EqualSums.java    | 27 ++++++++++++++++---
 .../sprint7/LevenshteinDistance.java          | 17 ++++++++----
 2 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/src/main/java/algorithms/sprint7/EqualSums.java b/src/main/java/algorithms/sprint7/EqualSums.java
index 0ab867e..f6f82c3 100644
--- a/src/main/java/algorithms/sprint7/EqualSums.java
+++ b/src/main/java/algorithms/sprint7/EqualSums.java
@@ -31,18 +31,30 @@
 Пространственная сложность — O(S / 64).
 */
 public class EqualSums {
+    private static final int MAX_GAMES = 300;
+    private static final int MAX_TOTAL = MAX_GAMES * 300;
 
     static boolean solve(int[] points) {
-        int total = 0;
+        if (points.length > MAX_GAMES) {
+            throw new IllegalArgumentException("Too many games");
+        }
+
+        long total = 0;
         for (int point : points) {
+            if (point < 0) {
+                throw new IllegalArgumentException("Point value is out of range");
+            }
             total += point;
+            if (total > MAX_TOTAL) {
+                throw new IllegalArgumentException("Total points are out of range");
+            }
         }
 
-        if ((total & 1) == 1) {
+        if ((total & 1L) == 1L) {
             return false;
         }
 
-        int target = total / 2;
+        int target = (int) (total / 2);
         long[] reachable = new long[(target >> 6) + 1];
         reachable[0] = 1L;
 
@@ -168,10 +180,17 @@ private static void run() throws Exception {
         FastOut out = new FastOut(System.out);
 
         int n = in.nextInt();
+        if (n < 0 || n > MAX_GAMES) {
+            throw new IOException("Number of games is out of range");
+        }
         int[] points = new int[n];
 
         for (int i = 0; i < n; i++) {
-            points[i] = in.nextInt();
+            int point = in.nextInt();
+            if (point < 0) {
+                throw new IOException("Point value is out of range");
+            }
+            points[i] = point;
         }
 
         out.writeAscii(solve(points) ? "True" : "False");
diff --git a/src/main/java/algorithms/sprint7/LevenshteinDistance.java b/src/main/java/algorithms/sprint7/LevenshteinDistance.java
index 482e1fb..2547124 100644
--- a/src/main/java/algorithms/sprint7/LevenshteinDistance.java
+++ b/src/main/java/algorithms/sprint7/LevenshteinDistance.java
@@ -27,8 +27,12 @@
 Пространственная сложность: O(min(n, m)), потому что хранится только две строки динамики.
 */
 public class LevenshteinDistance {
+    private static final int MAX_LINE_LENGTH = 1000;
 
     static int solve(String first, String second) {
+        if (first.length() > MAX_LINE_LENGTH || second.length() > MAX_LINE_LENGTH) {
+            throw new IllegalArgumentException("Input line is too long");
+        }
         String s = first;
         String t = second;
 
@@ -94,8 +98,8 @@ private int read() throws IOException {
             return buf[ptr++];
         }
 
-        String nextLine() throws IOException {
-            byte[] tmp = new byte[1024];
+        String nextLine(int maxLength) throws IOException {
+            byte[] tmp = new byte[Math.min(1024, maxLength + 1)];
             int size = 0;
             int c = read();
 
@@ -105,8 +109,11 @@ String nextLine() throws IOException {
 
             while (c != -1 && c != '\n') {
                 if (c != '\r') {
+                    if (size == maxLength) {
+                        throw new IOException("Input line is too long");
+                    }
                     if (size == tmp.length) {
-                        byte[] grown = new byte[tmp.length * 2];
+                        byte[] grown = new byte[Math.min(tmp.length * 2, maxLength)];
                         System.arraycopy(tmp, 0, grown, 0, tmp.length);
                         tmp = grown;
                     }
@@ -169,8 +176,8 @@ private static void run() throws Exception {
         FastIn in = new FastIn(System.in);
         FastOut out = new FastOut(System.out);
 
-        String s = in.nextLine();
-        String t = in.nextLine();
+        String s = in.nextLine(MAX_LINE_LENGTH);
+        String t = in.nextLine(MAX_LINE_LENGTH);
 
         out.writeInt(solve(s, t));
         out.writeByte('\n');