PAT甲级 1054. The Dominant Color (20)

题目：

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, 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 30 0 255 16777215 2424 24 0 0 2424 0 24 24 24

Sample Output:

24

思路：

用map，用scanf

代码：

#include<iostream>#include<map>#include<algorithm>using namespace std;//注意dominant color 超过半数int main(){//ifstream cin;//cin.open("case1.txt");int M, N;cin >> M >> N;map<int, int> color;int i, j,c;for (i = 0; i < N; ++i){for (j = 0; j < M; ++j){scanf("%d",&c);color[c]++;}}map<int, int>::iterator iter;for (iter = color.begin(); iter != color.end(); ++iter){if(iter->second>N*M/2){cout << iter->first << endl;break;}}system("pausse");return 0;}