标签:des style blog color io os ar for strong
[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:
1 #include<stdio.h> 2 3 int largestSubarray(int str[],int size) 4 { 5 int largest=0; 6 int i,j; 7 str[0]?(str[0]=1):(str[0]=-1); 8 // preprocess. 9 for(i=1;i<size;i++) 10 { 11 str[i]?(str[i]=str[i-1]+1):(str[i]=str[i-1]-1); 12 } 13 // find the last 0‘s position, and find the farther distance of the same numbers. 14 for(i=0;i<size;i++) 15 { 16 // find the last 0‘s position. 17 if(0 == str[i] && (i+1)>largest) 18 { 19 largest=i+1; 20 // printf("0:%d\n",largest); 21 } 22 // find the farther distance of the same numbers. 23 for(j=0;j<i;j++) 24 { 25 if(str[i] == str[j] && (i-j)>largest) 26 { 27 largest=i-j; 28 // printf("other:%d\n",largest); 29 break; 30 } 31 } 32 } 33 return largest; 34 } 35 36 int main() 37 { 38 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}; 39 int size=sizeof(str)/sizeof(str[0]); 40 int i; 41 42 printf("Initianl Sequence which size is %d :\n",size); 43 for(i=0;i<size;i++) 44 { 45 printf("%d, ",str[i]); 46 } 47 printf("\nlargest:%d\n",largestSubarray(str,size)); 48 }
[003] largest_subarray_with_equal_1&0
标签:des style blog color io os ar for strong
原文地址:http://www.cnblogs.com/lyutian/p/4043931.html