Returns the maximum number of sub-arrays in an integer array and

Member: Liu Wei Http://www.cnblogs.com/Lw-1573/p/5323542.html

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

Requirements: 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). 2. Design idea: The most difficult problem of this topic is how to find the sub-array and the time complexity is O (n); My idea is to start traversing the entire array from the left (A[0]) to the rightmost end (a[n-1]), and record the largest subarray and Maxsofar in the process so far. The Maxsofar is initialized to 0. What if we have found the largest sub-array between a[0] and A[n-1] and the largest subarray between a[0] and A[i]? The largest sub-array between "or a[0" to a[i-1] and ", or" from A[i, "the maximum number of consecutive numbers to go forward." In order to start from a[i], the maximum value of several consecutive numbers is used as follows: Starting from a[i] The maximum value of several consecutive numbers is maxending_i equal to (maxending_i-1) +a[i] and the maximum of 2, i.e. Maxending_i=max ((manending_i-1) +a[i],0) 3 code:

1 #include <iostream> 2 using namespace std; 3 int max (int a,int b) 4 {5     if (a>b) 6     {7        return A; 8     } 9     else10     {One        return b;12     }13} int maxsum (int a[], int n) {     0  int i;17 int Maxsofar The maximum value of the Maxsofar record so far is     maxendinghere = 0;//maxendinghere records the maximum value of the number of consecutive digits starting at the current position     (i = 0; i < n; i++)     {         maxendinghere = max (Maxendinghere + a[i], 0);         maxsofar = max (Maxsofar, maxendinghere); 23< C16/>}24     return maxsofar;25}26 int main () {     int n, i=0;29     cout<< "Please enter Number:";     >n;31     cout<< "Please enter an array:";     int a[100000]={0};33 for     (i=0;i<n;i++)         >>a[i];36     }37     int Max=maxsum (A, n);     cout << Maximum sub-array: << Max << endl;39     return 0;40}

4. Summary

At first it was intended to find each sub-array, and then to find the maximum value, when the program code is found to be troublesome, and a lot of code function is repeated, so I began to read the data structure of the last semester textbooks, to find the appropriate ideas for this topic. When I finish writing, I feel that if I start to define the length of the array, then the scope of the application is limited, so I think how to make the length of the array can be arbitrarily changed, and then I think of a freshman learning C + + When the pointer can define a dynamic array, so in the program used the pointer

Project Plan Summary:

Date/Task	Lectures	Writing Programs	Read related books	Total Day
Monday	110	60	120	290
Tuesday			120	120
Wednesday		60	120	180
Thursday	110	60	90	320
Friday		120	60	180
Saturday			60	60
Sunday			60 (PLAN)	60
Weekly totals	220	360	330	910

Time log:

Date	Start time	End time	Interrupt Time	NET time	Activities	Note
3/7	14:00	15:50	14:50	100	Class
	19:00	22:00		180	Reading	Human Moon Myth
3/8	19:00	22:00	20:30	180	Programming	Homework
3/9	19:00	22:00		180	Programming	Homework
3/10	14:00	15:50	14:50	100	Class	Software Unit Testing
	19:00	22:00		180	Reading	The method of construction
3/11	14:30	18:30		240	Study	Homework
3/12	8:00	11:30		210	Programming	Rest (Plan)
3/13	8:00	11:30		180	Review	Rest (Plan)

Bug log:

3/8

1

Design

Compile

10min

Dynamic planning

Returns the maximum number of sub-arrays in an integer array and