A1054

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

数的范围大,用map，怕超时用不排序的unordered_map

#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<unordered_map>
#include<cmath>
#include<set>
#include<queue>
#include<cstring>
#include<cstdio>
#include<algorithm>
using namespace std;

int main(){
    int n,m,a[850][650],x;
    cin>>n>>m;
    unordered_map<int,int>mp;
    for(int i=0;i<n;i++){
        for(int j=0;j<m;j++){
            scanf("%d",&x);
            mp[x]++;
        }   
    }
    int maxn=0,num;
    for(auto it=mp.begin();it!=mp.end();it++){
        if(maxn<it->second){
            num=it->first;
            maxn=it->second;
        }
    }
    cout<<num;
    return 0;
}