PAT甲级 1054 The Dominant Color （20 分）map，水题

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

题目大意：选取主色调，就是M列N行的矩阵里面出现次数多余一半的那个数字～

分析：STL中map的应用～使用arr[i] = j表示i元素在矩阵中出现了j次，在输入的同时比较arr当前的值是否已经超过半数，如果超过，就直接输出该数字并退出程序～

#include<iostream>
#include<stdio.h>
#include<map>
using namespace std;

int main(){
	int m,n,num;
	scanf("%d%d",&m,&n);
	map<int,int> mp;
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			scanf("%d",&num);
			mp[num] += 1;
		}
	}
	
	int res = -1;
	for(auto it:mp){
		if(it.second >= n*m/2)
			res = it.first;
	}
	printf("%d",res);
	
	return 0;
}