1054. The Dominant Color (20)

题目链接：http://www.patest.cn/contests/pat-a-practise/1054

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

分析：

因为是超过一半的相同的数，所以如果不同，则抵消，如果相同，则都留下，计数加1.

AC代码：

#include<stdio.h>int ans = -1 , idx = 0;int main(){//freopen("F://Temp/input.txt", "r", stdin); int m, n; scanf("%d%d", &m, &n); for (int i = 0; i < n; i++){  for (int j = 0; j < m; j++){   int tmp;   scanf("%d", &tmp);   if (ans == -1)ans = tmp;   else if (ans == tmp){    idx++;//计数   }   else if (ans != tmp){    if (idx != 0){     idx--;    }    else     ans = tmp;   }  } } printf("%d\n", ans); return 0;}

截图：

——Apie陈小旭