在"医院"Collection 中,有医院每个部门的文件.每个文件都有详细信息,如科室名称、分配给该科室的doctor 和护士.文档 struct 如下所示:
{
"department": "emergency_care",
"doctors": ["d1", "d2", "d3"],
"nurses": ["n1", "n2", "n3", "n4", "n5"]
},
{
"department": "child_health",
"doctors": ["d4", "d5"],
"nurses": ["n6"]
},
{
"department": "first_aid_room",
"nurses": ["n7", "n8"]
}
如何计算住院总人数,这是所有科室所有doctor 和护士的总和.
预期输出:13