1054 The Dominant Color(map 以及 STL的应用)

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 [0,2²⁴ ). 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:

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

Sample Output:

分析：
本题要求在给定的序列中找出超过半数并且占比最大的元素，考查map的用法。因为digital color最大值超过long long范围(9.22337e+018)，因此定义成string类型较为合适。

#include<iostream> 
#include <map>
using namespace std;
map<string,int> mp;
int main(){
	int m,n;
	cin>>m>>n;
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			string a;
			cin>>a;
			mp[a]++;
		}
	}
	string pixel;
	int maxcnt=0;
	for(auto it : mp){
		if(maxcnt<it.second){
			maxcnt=it.second;
			pixel=it.first;
		}
	}
	cout<<pixel;
	return 0;
}