sort函数是C++中自带的排序函数，包含在头文件 #include<algorithm> 的C++标准库中。
用sort函数排序比冒泡之类的算法效率要高
功能：对给定区间的所有元素进行排序，默认为升序，也可进行降序
可以直接对数组进行排序
SYNTAX:
sort(start, end, cmp);
start为数组的起始地址
end为数组结束地址的下一位
cmp为排序方式，可不填，默认升序
例：对年月日时间进行排序
1 #include<iostream> 2 #include<algorithm> 3 using namespace std; 4 class Date 5 { 6 public: 7 int year; 8 int month; 9 int day; 10 int hour; 11 int startminute; 12 int endminute; 13 }; 14 15 int main() 16 { 17 Date arry[100]; 18 void display(Date arry[], int n); 19 int n; 20 int i; 21 cout << "Please input the number of the date" << endl; 22 cin >> n; 23 cout << "Please enter year,month,day,hour,startminute,endminute in order" << endl; 24 for (i = 0; i < n; i++) 25 { 26 cin >> arry[i].year 27 >> arry[i].month 28 >> arry[i].day 29 >> arry[i].hour 30 >> arry[i].startminute 31 >> arry[i].endminute; 32 } 33 display(arry, n); 34 return 0; 35 } 36 void display(Date arry[], int n) 37 { 38 int compare(Date a, Date b); 39 int i; 40 sort(arry, arry + n, compare); 41 cout << "Here are all the sorted date:" << endl; 42 for (i = 0; i < n; i++) 43 { 44 cout << "start time(" << arry[i].year << "/" << arry[i].month << "/" << "/" << arry[i].day; 45 cout << " " << arry[i].hour << ":" << arry[i].startminute << ") - "; 46 cout << "end time(" << arry[i].year << "/" << arry[i].month << "/" << "/" << arry[i].day; 47 cout << " " << arry[i].hour << ":" << arry[i].endminute << ")" << endl; 48 cout << "------------------------------------------" << endl; 49 50 } 51 } 52 53 int compare(Date a, Date b) 54 { 55 if (a.year == b.year) 56 { 57 if (a.month == b.month) 58 { 59 if (a.day == b.day) 60 { 61 if(a.hour == b.hour) 62 { 63 return a.startminute<b.startminute; 64 } 65 else 66 { 67 return a.hour < b.hour; 68 } 69 } 70 else 71 { 72 return a.day < b.day; 73 } 74 75 } 76 else 77 { 78 return a.month < b.month; 79 } 80 } 81 else 82 { 83 return a.year < b.year; 84 } 85 }
ps: 新手初学C++