void prog1_static(void) { int pos = 9; // elem will hold the element‘s value vector<int> *elem; elem = fibon_seq2(pos); cout << elem->size() << endl; for (int in = 0; in < elem->size(); in++) { cout << elem[0][in] <<" "; } cout << endl; pos = 18; elem = fibon_seq2(pos); cout << elem->size() << endl; for (int in = 0; in < elem->size(); in++) { cout << elem[0][in] <<" "; //error } cout << endl; }
下面的函数返回elems的地址。可以返回静态对象的地址
通过去读取vector的返回值可以实现减少计算工作量的方法。
cout << elem[0][in] <<" ";
这个用法一定要注意,试了很就才发现。
elem是一个向量指针,这个指针指向某一个向量的,
因此类似于c语言中一个指针指向二位数组。
vector<int> *fibon_seq2( int size ) { const int max_size = 1024; static vector< int > elems; if ( size <= 0 || size > max_size ) { cerr << "fibon_seq(): oops: invalid size: " << size << " -- can锟絫 fulfill request.\n"; return 0; } // if size is equal to or greater than elems.size(), // no calculations are necessary ... for ( int ix = elems.size(); ix < size; ++ix ) { if ( ix == 0 || ix == 1 ) { elems.push_back( 1 ); } else { elems.push_back( elems[ix - 1] + elems[ix - 2] ); } } return &elems; }
原文地址:https://www.cnblogs.com/CodeWorkerLiMing/p/11221428.html
时间: 2024-10-02 23:26:28