From 000a1d3bedb5438ee2a51f63bd304490bb69eac5 Mon Sep 17 00:00:00 2001
From: sanerror <237606586@qq.com>
Date: Sun, 16 Oct 2016 16:36:03 +0800
Subject: [PATCH 1/3] Update ex9_43

`erase()` may affect the existed iterator `beg`;
and improve the intelligibility.
---
 ch09/ex9_43.cpp | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/ch09/ex9_43.cpp b/ch09/ex9_43.cpp
index 3d5ede7e..7ea91c88 100644
--- a/ch09/ex9_43.cpp
+++ b/ch09/ex9_43.cpp
@@ -18,18 +18,17 @@ using std::string;
 
 void Replace(string& s, const string& oldVal, const string& newVal)
 {
-    for (auto beg = s.begin(); beg != s.end(); ++beg) {
-        if (*beg != oldVal.front()) continue;
-        if (std::distance(beg, s.end()) <
-            std::distance(oldVal.begin(), oldVal.end()))
-            break;
-        if (string{beg, beg + oldVal.size()} == oldVal) {
-            auto pos = std::distance(s.begin(), beg);
-            s.erase(beg, beg + oldVal.size());
-            s.insert(beg, newVal.cbegin(), newVal.cend());
-            beg = std::next(s.begin(), pos + newVal.size() - 1);
-        }
-    }
+	for (auto beg = s.begin(); beg != s.end(); ) {
+		++beg;
+		if (*beg != oldVal.front()) continue; 
+		if (std::distance(beg, s.end()) <
+			std::distance(oldVal.begin(), oldVal.end()))
+			break;
+		if (string{ beg, beg + oldVal.size() } == oldVal) {
+			beg = s.erase(beg, beg + oldVal.size());
+			beg = s.insert(beg, newVal.cbegin(), newVal.cend()) + newVal.size();
+		}
+	}
 }
 
 int main()

From 6c4e66f8bcb4451fcb4d7c7bb1d65b7fac59ed88 Mon Sep 17 00:00:00 2001
From: sanerror <237606586@qq.com>
Date: Sun, 16 Oct 2016 16:42:23 +0800
Subject: [PATCH 2/3] Update ex9_43.cpp

---
 ch09/ex9_43.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/ch09/ex9_43.cpp b/ch09/ex9_43.cpp
index 7ea91c88..3c63372a 100644
--- a/ch09/ex9_43.cpp
+++ b/ch09/ex9_43.cpp
@@ -3,6 +3,7 @@
 //  Exercise 9.43
 //
 //  Created by pezy on 6/18/15.
+//  Updated by sanerror on 10/16/16.
 //  Copyright (c) 2014 pezy. All rights reserved.
 //
 //  @Brief  Write a function that takes three strings, s, oldVal, and newVal.

From b39e9008dc20a16f9fc5c736c9ffb304b0668162 Mon Sep 17 00:00:00 2001
From: sanerror <237606586@qq.com>
Date: Sun, 16 Oct 2016 21:30:46 +0800
Subject: [PATCH 3/3] Update ex9_43.cpp

---
 ch09/ex9_43.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/ch09/ex9_43.cpp b/ch09/ex9_43.cpp
index 3c63372a..00489668 100644
--- a/ch09/ex9_43.cpp
+++ b/ch09/ex9_43.cpp
@@ -20,18 +20,18 @@ using std::string;
 void Replace(string& s, const string& oldVal, const string& newVal)
 {
 	for (auto beg = s.begin(); beg != s.end(); ) {
-		++beg;
-		if (*beg != oldVal.front()) continue; 
 		if (std::distance(beg, s.end()) <
 			std::distance(oldVal.begin(), oldVal.end()))
 			break;
-		if (string{ beg, beg + oldVal.size() } == oldVal) {
+		if (*beg == oldVal.front() && string{ beg, beg + oldVal.size() } == oldVal) {
 			beg = s.erase(beg, beg + oldVal.size());
 			beg = s.insert(beg, newVal.cbegin(), newVal.cend()) + newVal.size();
 		}
+		else {
+			++beg;
+		}
 	}
 }
-
 int main()
 {
     {