1054 The Dominant Color (20分)【map】

1054 The Dominant Color (20分)

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 [0,2​24​​). 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:

5 3
0 0 255 16777215 24
24 24 0 0 24
24 0 24 24 24

Sample Output:

24

解题思路：

这道题目给你一个N行M列的数字矩阵，求其中超过半数的出现次数最多的数字。我们可以使用map来求解，方便快速，而且如果我们使用普通的数组可能会由于数据范围过大，可能导致内存超限。

#include<iostream>
#include<map>
using namespace std;

int main()
{
	int n, m, col;
	map<int, int>count;
	scanf("%d %d", &n, &m);
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
		{
			scanf("%d", &col);
			if (count.find(col) != count.end())    //如果存在则计数加1
				count[col]++;
			else
				count[col] = 1;
		}
	}
	int k = 0, MAX = 0;
	for (map<int, int>::iterator it = count.begin(); it != count.end(); it++)
	{
		if (it->second > MAX)
		{
			k = it->first;
			MAX = it->second;
		}
	}
	printf("%d\n", k);
	return 0;
}