nyoj 107 排序问题之A Famous ICPC Team

/*
A Famous ICPC Team
时间限制：1000 ms  |  内存限制：65535 KB
难度：2
描述
Mr. B, Mr. G, Mr. M and their coach Professor S are planning their way to Warsaw for the ACM-ICPC World Finals. Each of the four has a square-shaped suitcase with side length Ai (1<=i<=4) respectively. They want to pack their suitcases into a large square box. The heights of the large box as well as the four suitcases are exactly the same. So they only need to consider the large box’s side length. Of course, you should write a program to output the minimum side length of the large box, so that the four suitcases can be put into the box without overlapping.
输入
Each test case contains only one line containing 4 integers Ai (1<=i<=4, 1<=Ai<=1,000,000,000) indicating the side length of each suitcase.
输出
For each test case, display a single line containing the case number and the minimum side length of the large box required.
样例输入
2 2 2 2
2 2 2 1
样例输出
Case 1: 4
Case 2: 4
提示
For the first case, all suitcases have size 2x2. So they can perfectly be packed in 
a 4x4 large box without wasting any space.
For the second case, three suitcases have size 2x2 and the last one is 1x1. No
matter how you rotate or move the suitcases, the side length of the large box must
be at least 4.
来源
hdu
上传者
李如兵

*/

题意：

       四个箱子放到一个大盒子里，大盒子的高度与四个箱子一样。现在求出大盒子的边长，只要找出4个箱子中，最大的两个箱子的边长就行了，再把最大的两个输出就行！

#include<cstdio>
#include<stdlib.h>
#include<algorithm>
using namespace std;
double a[4];
int main()
{
int ca=1;
while(~scanf("%lf%lf%lf%lf",&a[0],&a[1],&a[2],&a[3]))
{
sort(a,a+4);//c++默认从小到大排序：
printf("Case %d: %.0lf\n",ca++,a[2]+a[3]);
}
return 0;
}