1323区间合并（贪心算法），c++

#include
#include
#include

using namespace std;

struct interval
{
    int left;
    int right;
};
bool compare(interval x,interval y)
{
    return x.left<y.left;
}
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        interval arr[n];
        for(int i=0;i<n;i++)
            scanf("%d%d",&arr[i].left,&arr[i].right);
        sort(arr,arr+n,compare);//根据左端点从小到大排序
        
        interval ans[n];
        ans[0].left=arr[0].left,ans[0].right=arr[0].right;//初始化
        int index=0;//index指向ans数组末位 
        
        for(int i=1;i<n;i++)
        {
            if(ans[index].right>=arr[i].left&&ans[index].right<arr[i].right)//未完全重叠
                ans[index].right=arr[i].right;
            else if(ans[index].right<arr[i].left)//未重叠
            {
                ans[++index].left=arr[i].left;
                ans[index].right=arr[i].right;
            }
        }
        
        printf("%d\n",index+1);
        for(int i=0;i<=index;i++)
            printf("%d %d\n",ans[i].left,ans[i].right);
    }
    return 0;
}