[003] largest_subarray_with_equal_1&0

[Description] Given an array with only '1' and '0', find a largest length sub-array which contains equal number of '1' and '0'. Return the largest number.

e.g. arr[] = {1,0,1,0,0,0,1,1,0,1,1,0,1,1,1,0,0,1,1,1,0,1,0,1,1}

　　return : 16

[Thought] Preprocess this array by add 1/-1 to arr[i] while arr[i] is 1/0; find the last position of '0' as 'largest1'; find the farther distance of the same number as 'largest2'; return the larger one of 'largest1' and 'largest2'.　　O(n^2)

[Implementation] C code:

#include<stdio.h>

int largestSubarray(int str[],int size)
{
        int largest=0;
        int i,j;
        str[0]?(str[0]=1):(str[0]=-1);
        // preprocess.
        for(i=1;i<size;i++)
        {
                str[i]?(str[i]=str[i-1]+1):(str[i]=str[i-1]-1);
        }
        // find the last 0's position, and find the farther distance of the same numbers.
        for(i=0;i<size;i++)
        {
                // find the last 0's position.
                if(0 == str[i] && (i+1)>largest)
                {
                        largest=i+1;
//                      printf("0:%d\n",largest);
                }
                // find the farther distance of the same numbers.
                for(j=0;j<i;j++)
                {
                        if(str[i] == str[j] && (i-j)>largest)
                        {
                                largest=i-j;
//                              printf("other:%d\n",largest);
                                break;
                        }
                }
        }
        return largest;
}

int main()
{
        int str[]={1,0,1,0,0,0,1,1,0,1,1,0,1,1,1,0,0,1,1,1,0,1,0,1,1};
        int size=sizeof(str)/sizeof(str[0]);
        int i;

        printf("Initianl Sequence which size is %d :\n",size);
        for(i=0;i<size;i++)
        {
                printf("%d, ",str[i]);
        }
        printf("\nlargest:%d\n",largestSubarray(str,size));
}