Update searchCube_v1.1.cpp

多线程查找

ALG/math/findSpecialCube/searchCube_v1.1.cpp

@@ -9,50 +9,76 @@ bool is_perfect_square(long long n) {
     return sqrt_n * sqrt_n == n;
 }
 
-void find_cuboid(long long max_length) {
+void find_cuboid(int threadId, long long start_number, long long max_length) {
+
     static long long searchTimes =0;
-    for (long long a = 1; a <= max_length; a++) {
+    for (long long a = start_number; a <= max_length; a++) {
  //a,b,c不可能相等
         for (long long b = a+1; b <= max_length; b++) {
             long long c2 = a * a + b * b;
             long long c = static_cast<long long>(std::sqrt(c2));
-            searchTimes++;
+            {
+              std::lock_guard<std::mutex> lock(g_time_mutex);
+              searchTimes++;
+            }
 // a+b+c必定是偶数，根据a^2+b^2+c^2=p^2等推出
             //if((a+b+c)%2 !=0) continue;
 
             if((a+b) < c) continue;
             if((a+c) < b) continue;
+            if(a==b||a==c||b==c) continue; //add 两边相等，不符合 08.20
               //b+c>a+1>a
+            //cout <<"threadId:" <<threadId <<"searchTimes:"<<searchTimes<<endl;
             if(searchTimes%10000==0)
-             {cout <<"searchTimes:"<<searchTimes<<endl;
-             finCube <<"searchTimes:"<<searchTimes<< "step,try a cube" <<"a|b|c:" <<a<<","<<b <<","<<c<<endl;
-                     }
+             {cout <<"threadId:" <<threadId <<"searchTimes:"<<searchTimes<<endl;
+                 if(a>20 && b>20 && c>20){
+
+                    cout <<"searchTimes:"<<searchTimes<< "step,try a cube" <<"a|b|c:" <<a<<","<<b <<","<<c<<endl;
+                  }
+               }
+
             if(b%2000==0){printf("b is %lld\n",b);}
             if (c * c != c2) continue;  // 剪枝
             if(c%2000 ==0 || (a+b+c)%30 ==0)
             {
-               finCube << "step,try a cube" <<"a|b|c:" <<a<<","<<b <<","<<c<<endl;
+                std::lock_guard<std::mutex> lock(g_time_mutex);
+                    finCube << "step,try a cube" <<"a|b|c:" <<a<<","<<b <<","<<c<<endl;
              }
             long long sum2 = a * a + b * b + c * c;
             if (is_perfect_square(sum2)) {
+                 std::lock_guard<std::mutex> lock(g_time_mutex);
                  finCube << "find a cube" <<"a|b|c:" <<a<<""<<b <<""<<c<<endl;
+
                 std::cout << "长方体的边长为: a = " << a << ", b = " << b << ", c = " << c << std::endl;
             }
         }
     }
 }
 
-int main() 
+int main()
 {
-    long long max_length = 1000000000;
-     string fileName="numberCube2024.txt";
+    long long max_length = pow(2,45)-1;
+    long long oneStepBaseNumber=1e8;
+     string fileName="numberCube202409.txt";
   //ofstream  finCube;
   finCube.open(fileName);
   if(!finCube.is_open()){
    cerr<<"open file failed!\n";
    return -1;
   }
+  cout <<"start to find\n";
+    const int threadCount=1;
+    thread th[10];
+    for(int i=0 ;i<5; i++)
+    {
+    th[i] = thread(find_cuboid, i, 1+oneStepBaseNumber*(i+1), max_length);
+    };
+    for (int i = 0; i < threadCount; i++) {
+        th[i].join(); // 等待所有线程完成
+    }
+
+    finCube.close(); // 关闭文件
 
-    find_cuboid(max_length);
     return 0;
 }
+