PAT 01-1. Max Sub Columns and problems (20)

01-1. Max sub-columns and questionsTime limit 10000 ms
Memory Limit 65536 KB
Code length limit 8000 B
The Standard of the Judgment procedure

Given the sequence of K-integers {N1, N2, ..., NK}, "contiguous sub columns" are defined as {Ni, ni+1, ..., Nj}, where 1 <= i <= J <= K. Maximum sub columns and is defined as the largest of all contiguous child column elements. For example, given the sequence {-2, 11,-4, 13,-5,-2}, its contiguous sub columns {11,-4, 13} have the largest and 20. You are asked to write a program that calculates the maximum number of columns for a given integer sequence.

Input Format:

The input line 1th gives a positive integer k (<= 100000), and line 2nd gives K integers, which are separated by spaces.

output Format:

Outputs the largest columns in a row. If all integers in the sequence are negative, the output is 0. Input Sample:

6
-2 11-4 13-5-2

Output Sample:

20

/*
PROBLEM: Max Sub column and Problem
solving method: Online processing
time complexity: O (n)/

#include <stdio.h>
#include <malloc.h>

int findseq (int n,int list[]);//online processing

int main ()
{
	int length,i;
	int *list;
	int max=0;
	scanf ("%d", &length);
	List= (int*) calloc (length,sizeof (int));
	for (i=0;i<length;i++) {
		scanf ("%d", &list[i]);
	Max=findseq (length,list);
	printf ("%d", max);
	return 0;
}

int findseq (int n,int list[]) {
	int thissum,maxsum=0;
	int i;
	thissum=0;
	for (i=0;i<n;i++) {
		thissum+=list[i];	
		if (thissum>maxsum)
			maxsum=thissum;
		else if (thissum<0)
				thissum=0;
	}
	return maxsum;
}