1054 The Dominant Color (20)

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, 800x600), 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：给一个m*n的数组，找出数字相同，且个数超过m*n/2，的数字
思路：用map类型来保存数字以及个数。然后再遍历map找到数字相同且个数最多的数字；

 1 #include<iostream>
 2 #include<map>
 3 using namespace std;  
 4 int main(){
 5   int m, n, half;
 6   cin>>m>>n;
 7   map<int, int> mm;
 8   half = m*n/2;
 9   for(int i=0; i<m*n; i++) {
10    int temp;
11    scanf("%d", &temp);
12    if(mm.count(temp)==0) mm[temp]=1;
13    else mm[temp]++;
14   }
15   for(auto it=mm.begin(); it!=mm.end(); it++){
16     if(it->second > half) {cout<<it->first<<endl;break;}
17   }
18   return 0;
19 }