Fix multilingual content typos (#1958)

en/docs/chapter_dynamic_programming/summary.md

@@ -21,5 +21,5 @@
 **Edit distance problem**
 
 - Edit distance (Levenshtein distance) is used to measure the similarity between two strings, defined as the minimum number of edit steps from one string to another, with edit operations including insert, delete, and replace.
-- The state definition for the edit distance problem is the minimum number of edit steps required to change the first $i$ characters of $s$ into the first $j$ characters of $t$. When $s[i] \ne t[j]$, there are three decisions: insert, delete, replace, each with corresponding remaining subproblems. From this, the optimal substructure can be identified and the state transition equation constructed. When $s[i] = t[j]$, no edit is required for the current character.
+- The state definition for the edit distance problem is the minimum number of edit steps required to change the first $i$ characters of $s$ into the first $j$ characters of $t$. When $s[i-1] \ne t[j-1]$, there are three decisions: insert, delete, replace, each with corresponding remaining subproblems. From this, the optimal substructure can be identified and the state transition equation constructed. When $s[i-1] = t[j-1]$, no edit is required for the current character.
 - In edit distance, the state depends on the state directly above, directly to the left, and to the upper-left, so after space optimization, neither forward nor reverse traversal can correctly perform state transitions. For this reason, we use a variable to temporarily store the upper-left state, thus transforming to a situation equivalent to the unbounded knapsack problem, allowing for forward traversal after space optimization.