Behind the scenes in the computer’s memory, color is always talked about as a series of 24 bits of information for each pixel. In an image, the color with the largest proportional area is called the dominant color. A strictly dominant color takes more than half of the total area. Now given an image of resolution M by N (for example, 800×600), you are supposed to point out the strictly dominant color.
Input Specification:
Each input file contains one test case. For each case, the first line contains 2 positive numbers: M (<=800) and N (<=600) which are the resolutions of the image. Then N lines follow, each contains M digital colors in the range [0, 224). It is guaranteed that the strictly dominant color exists for each input image. All the numbers in a line are separated by a space.
Output Specification:
For each test case, simply print the dominant color in a line.
Sample Input:
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5 3 0 0 255 16777215 24 24 24 0 0 24 24 0 24 24 24 |
Sample Output:
1 |
24 |
直接遍历会超时,hashing 可以过……不知最优解是什么
代码如下:
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#include<stdio.h> #include<stdlib.h> #include<memory.h> typedef struct hashtable_ { int number; int count; } hashtable; int main() { int m,n,temp,i,j,count,total,size,pos,offset,max; hashtable *table; scanf("%d%d",&m,&n); total=m*n; if(total%2==0) { size=total+1; } else { size=total; } table=(hashtable *)malloc(size*sizeof(hashtable)); memset(table,0xFF,size*sizeof(hashtable)); for(i=0;i<total;i++) { scanf("%d",&temp); pos=temp%size; offset=0; while(table[pos].number!=-1&&table[pos].number!=temp) { pos+=(offset<<1)+1; pos%=size; } table[pos].number=temp; table[pos].count++; if(table[pos].count+1>total/2) { break; } } printf("%d\n",table[pos].number); } |