3. Software engineering knot pair development The sum of successive maximal sub-arrays in a one-dimensional array and the determination of overflow

First, the topic requirements

Title: Returns the and of the largest sub-array in an integer array.

Requirement: The procedure must be capable of handling 1000 elements;

Each element is of the int32 type;

Enter an array of shapes, with positive numbers in the array and negative values;

One or more consecutive integers in an array make up a sub-array, each of which has a and;

The maximum value for the and of all sub-arrays. Requires a time complexity of O (n);

Results can be judged after overflow.

Second, the design idea

In our previous program, because the int type rand () randomly produces a number range of 0~32767, the resulting 1000 number is smaller and does not produce an overflow. However, we find that the maximum number of Int32 is 2147360000 or 2^31, if the result overflow will prompt overflow.

Third, the source code

1#include <iostream.h>2#include <stdlib.h>3#include <time.h>4 voidMain ()5 {6      while(1)7     {8         intlength,temp;9         int*arr=New int[length];Tencout<<"Please enter the length of the array:"; OneCin>>length; A         //cout<< "Please enter this array:"; - Srand ((unsigned) time (NULL)); -          for(intI=0; i<length;i++) the         { -Arr[i]=rand () *10000; -Temp=rand ()%2; -             if(temp==0) +             { -arr[i]=Arr[i]; +             } A             Else at             { -arr[i]=-Arr[i]; -             } -cout<<arr[i]<<"\ t"; -         } -         intresult = arr[0]; in         intsum = arr[0]; -          for(i=1; i<length;i++) to         { +             if(Sum >0) -             { theSum + =Arr[i]; *             } $             ElsePanax Notoginseng             { -sum =Arr[i]; the             } +             if(Sum >result) Aresult =sum; the         } +         if(result<2147360000|| result==2147360000) -         { $cout<<"the sum of the largest contiguous subarray in the array is:"<<result<<Endl; $         } -         Else -         { thecout<<"overflow beyond the maximum range!"<<Endl; -         }Wuyicout<<"----------------------------------------"<<Endl; the     } -}

Iv. Results

Five, the Experiment experience

We used to do experiments, always think too naïve, take it for granted that the user input must be entered according to our requirements, but the reality is not so, for the large number of overflow problem we are ill-conceived, there are other details of the problem we have many did not consider. When the input array length is large, it is likely to overflow, in the future to pay more attention!

VI. Cooperation Photos

3. Software engineering knot pair development The sum of successive maximal sub-arrays in a one-dimensional array and the determination of overflow