修复可能越界的bug

soulmachine · soulmachine · commit 86ecfeeeea4b · 2014-05-25T17:40:44.000-07:00
diff --git a/C++/chapDFS.tex b/C++/chapDFS.tex
@@ -63,7 +63,7 @@ \subsubsection{深搜1}
     }
 
     bool isPalindrome(const string &s, int start, int end) {
-        while (s[start] == s[end]) {
+        while (start < end && s[start] == s[end]) {
             ++start;
             --end;
         }
@@ -101,7 +101,7 @@ \subsubsection{深搜2}
         }
     }
     bool isPalindrome(const string &s, int start, int end) {
-        while (s[start] == s[end]) {
+        while (start < end && s[start] == s[end]) {
             ++start;
             --end;
         }

Original file line number	Diff line number	Diff line change
`@@ -63,7 +63,7 @@ \subsubsection{深搜1}`
`63`	`63`	`}`
`64`	`64`
`65`	`65`	`bool isPalindrome(const string &s, int start, int end) {`
`66`		`- while (s[start] == s[end]) {`
	`66`	`+ while (start < end && s[start] == s[end]) {`
`67`	`67`	`++start;`
`68`	`68`	`--end;`
`69`	`69`	`}`
`@@ -101,7 +101,7 @@ \subsubsection{深搜2}`
`101`	`101`	`}`
`102`	`102`	`}`
`103`	`103`	`bool isPalindrome(const string &s, int start, int end) {`
`104`		`- while (s[start] == s[end]) {`
	`104`	`+ while (start < end && s[start] == s[end]) {`
`105`	`105`	`++start;`
`106`	`106`	`--end;`
`107`	`107`	`}`