Solving the problem of maximal sub-array by divide and conquer

Solving the problem of maximal sub-array by divide-and-conquer method (to get the maximum and sub-arrays in the array for the given array)

/ * For a given integer array A, the number of arrays with the largest and the largest and the left and right subscript * Ideas: The method of dividing the array into two parts, there are three cases of the largest and sub-arrays * on the left of the array, at the right of the array, across the midpoint of the array */#include <iostream>using namespace Std;//structure for storing left and right boundary values and sum values/ * Pay special attention to the use of structures!!!!!!!!!!! */struct sumborder{intLeft//Left Border subscript    intRight//Right Border subscript    int sum;array elements between the//left and right boundaries};//Find across mid-midpoint, in array A[low: High] and the maximum number of sub-arraysSumborder *findmaxcrosssubarray (int*ptra,intLowintMidintHigh) {/* Get the max and * * on the left of mid    intLeftsum = Ptra[mid];//Left Max and    intMaxleft = mid;//Left Border    int sum=0; for(inti = mid; I >= low; i--) {sum+ = Ptra[i];if(sum>= leftsum) {leftsum =sum;        Maxleft = i; }    }/ * Get mid+1 and Right max and */    intRightsum = Ptra[mid +1];intMaxright = mid +1;sum=0; for(intj = Mid +1; J <= High; J + +) {sum+ = Ptra[j];if(sum>= rightsum) {rightsum =sum;        Maxright = j; }    }/ * Statistics Summary * /Sumborder Sumborder;    Sumborder *ptr = &sumBorder;    Ptr->left = Maxleft;    Ptr->right = Maxright; Ptr->sum= Leftsum + rightsum; cout << Ptr->left <<"-"<< Ptr->right <<"sum:"<< ptr->sum<< Endl;returnPTR;}/* Get the maximum subarray of array a (from low to High) and/*Sumborder *findmaxsubarray (int*ptra,intLowintHigh) {Sumborder sumborder; Sumborder *sumborderptr = &sumBorder;if(High = = Low)        {sumborder.left = low;        Sumborder.right = high; Sumborder.sum= Ptra[low]; }Else{intMid = (low + high)/2;//Get structure pointer variables in three cases and make further judgmentsSumborder *left = Findmaxsubarray (PtrA, Low, mid); Sumborder *right = Findmaxsubarray (PtrA, Mid +1, high); Sumborder *cross = Findmaxcrosssubarray (PtrA, Low, Mid, high);if(left->sum>= right->sum&& left->sum>= cross->sum) {Sumborder.left = left->left;            Sumborder.right = left->right; Sumborder.sum= left->sum; }Else if(right->sum>= left->sum&& right->sum>= cross->sum) {Sumborder.left = right->left;            Sumborder.right = right->right; Sumborder.sum= right->sum; }Else{Sumborder.left = cross->left;            Sumborder.right = cross->right; Sumborder.sum= cross->sum; }} cout << sumborderptr->left <<"-"<< Sumborderptr->right <<"Maximum value is:"<< sumborderptr->sum<< Endl;returnSumborderptr;}intMain () {//The given array    intA[] = {0, -, -3, - -, -, -3, - -, - at, -, -, -7, A, -5, - A, the, -4, -7};    Sumborder Sumborder;    Sumborder *ptr = &sumBorder; Sumborder *test = Findmaxsubarray (A,1, -);//Eat a big loss! Ptr->left = test->left;    Ptr->right = test->right; Ptr->sum= test->sum;/ * Replace the above with this is wrong, carefully study the struct structure body!!    Sumborder *ptr = Findmaxsubarray (A, 1, 16);    cout << "Left:" << ptr->left << Endl;    cout << "right:" << ptr->right << Endl;    cout << "sum:" << ptr->sum << Endl; */cout <<"The largest subarray of array A and is:"<< Endl; cout <<"Left:"<< ptr->left << Endl; cout <<"Right:"<< ptr->right << Endl; cout <<"sum:"<< ptr->sum<< Endl; System"Pause >> cout");return 0;}

Solving the problem of maximal sub-array by divide and conquer