Fix errors in subsum.cpp

clin99 · clin99 · commit ef077255f1ed · 2018-09-12T11:49:43.000-05:00
diff --git a/example/subsum.cpp b/example/subsum.cpp
@@ -15,7 +15,7 @@ constexpr auto total = 1u << tree_height;
 void update_max(std::atomic<int>& max_val, int const& value)
 {
   int old = max_val;
-  while(old < value and not max_val.compare_exchange_weak(old, value));
+  while(old < value && !max_val.compare_exchange_weak(old, value));
 }
 
 int maxCrossingSum(std::vector<int>& vec, int l, int m, int r){  
@@ -49,7 +49,7 @@ void maxSubArraySum(std::vector<int>& vec, int l, int r, std::atomic<int>& max_n
   // Base Case: Only one element 
   if (l == r) {
     update_max(max_num, vec[l]);  
-    if(++counter == total){
+    if(++counter == total*2-1){
       promise.set_value();
     }
     return ;
@@ -62,7 +62,7 @@ void maxSubArraySum(std::vector<int>& vec, int l, int r, std::atomic<int>& max_n
   tp.silent_async([&, m=m, r=r](){ maxSubArraySum(vec, m+1, r, max_num, tp, counter, promise); });
 
   update_max(max_num, maxCrossingSum(vec, l, m, r));
-  if(++counter == total){
+  if(++counter == total*2-1){
     promise.set_value();
   }
 } 
@@ -82,7 +82,7 @@ auto subsum(std::vector<int>& vec){
   }
   auto end = std::chrono::high_resolution_clock::now();
   auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
-  //std::cout << result << '\n';
+  //std::cout << counter << '\n';
   return elapsed.count();
 }
 

Original file line number	Diff line number	Diff line change
`@@ -15,7 +15,7 @@ constexpr auto total = 1u << tree_height;`
`15`	`15`	`void update_max(std::atomic<int>& max_val, int const& value)`
`16`	`16`	`{`
`17`	`17`	`int old = max_val;`
`18`		`- while(old < value and not max_val.compare_exchange_weak(old, value));`
	`18`	`+ while(old < value && !max_val.compare_exchange_weak(old, value));`
`19`	`19`	`}`
`20`	`20`
`21`	`21`	`int maxCrossingSum(std::vector<int>& vec, int l, int m, int r){`
`@@ -49,7 +49,7 @@ void maxSubArraySum(std::vector<int>& vec, int l, int r, std::atomic<int>& max_n`
`49`	`49`	`// Base Case: Only one element`
`50`	`50`	`if (l == r) {`
`51`	`51`	`update_max(max_num, vec[l]);`
`52`		`- if(++counter == total){`
	`52`	`+ if(++counter == total*2-1){`
`53`	`53`	`promise.set_value();`
`54`	`54`	`}`
`55`	`55`	`return ;`
`@@ -62,7 +62,7 @@ void maxSubArraySum(std::vector<int>& vec, int l, int r, std::atomic<int>& max_n`
`62`	`62`	`tp.silent_async([&, m=m, r=r](){ maxSubArraySum(vec, m+1, r, max_num, tp, counter, promise); });`
`63`	`63`
`64`	`64`	`update_max(max_num, maxCrossingSum(vec, l, m, r));`
`65`		`- if(++counter == total){`
	`65`	`+ if(++counter == total*2-1){`
`66`	`66`	`promise.set_value();`
`67`	`67`	`}`
`68`	`68`	`}`
`@@ -82,7 +82,7 @@ auto subsum(std::vector<int>& vec){`
`82`	`82`	`}`
`83`	`83`	`auto end = std::chrono::high_resolution_clock::now();`
`84`	`84`	`auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);`
`85`		`- //std::cout << result << '\n';`
	`85`	`+ //std::cout << counter << '\n';`
`86`	`86`	`return elapsed.count();`
`87`	`87`	`}`
`88`	`88`