算法-MergeSort
1 #include <iostream> 2 #include <vector> 3 #include <iterator> 4 5 using namespace std; 6 7 int COMPARE_COUNT = 0; 8 9 void merge_sort(vector<int> &array, vector<int> &aux, int lo, int hi) 10 { 11 if ( lo >= hi ) 12 return; 13 14 int mid = ( hi + lo ) / 2; 15 merge_sort(array, aux, lo, mid); 16 merge_sort(array, aux, mid + 1, hi); 17 18 //vector<int> aux; 19 for ( int i = lo; i < hi +1; ++i ) 20 aux[i] = array[i]; 21 22 int i = lo; 23 int j = mid + 1; 24 int k = lo; 25 26 while ( k < hi + 1 ) 27 { 28 if ( i > mid ) array[k++] = aux[j++]; 29 else if ( j > hi ) array[k++] = aux[i++]; 30 else if ( aux[i] <= aux[j] ) 31 { 32 array[k++] = aux[i++]; 33 COMPARE_COUNT++; 34 } 35 else{ 36 array[k++] = aux[j++]; 37 COMPARE_COUNT++; 38 } 39 } 40 41 return; 42 } 43 44 void Print(const vector<int> &array) 45 { 46 vector<int>::const_iterator _begin = array.begin(); 47 while ( _begin != array.end() ) 48 cout<<*_begin++<<" "; 49 50 cout<<endl; 51 } 52 53 int main() 54 { 55 cout<<"Please input the size of the array: "; 56 int size; 57 cin>>size; 58 59 vector<int> array; 60 for ( int i = 0; i < size; ++i ) 61 array.push_back( rand() % size + 1); 62 63 cout<<"The shuffling array is:"<<endl; 64 Print(array); 65 66 vector<int> aux; 67 aux.resize(array.size()); 68 //aux = array; 69 merge_sort(array, aux, 0, size - 1); 70 71 cout<<"The sorted array is:"<<endl; 72 Print(array); 73 74 //cout<<"Comparing count is: "<<COMPARE_COUNT<<endl; 75 76 return 0; 77 }
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