programming-examples/c++/_Basic/Comparator.cpp
2019-11-15 12:59:38 +01:00

38 lines
894 B
C++

#include <algorithm>
#include <set>
#include <iostream>
using namespace std;
struct item {
int x, y;
bool operator<(const item &o) const {
return x < o.x || x == o.x && y < o.y;
}
};
struct item_cmp {
bool operator()(const item &a, const item &b) {
return a.x < b.x || a.x == b.x && a.y < b.y;
}
};
bool cmp(const item &a, const item &b) {
return a.x < b.x || a.x == b.x && a.y < b.y;
}
int main() {
item a[] = { { 2, 3 }, { 1, 2 } };
//typedef set<item, bool(*)(const item&, const item&)> myset;
//myset s(a, a + 2, cmp);
//typedef set<item, item_cmp> myset;
typedef set<item> myset;
myset s(a, a + 2);
for (myset::iterator it = s.begin(); it != s.end(); it++) {
cout << it->x << " " << it->y << endl;
}
sort(a, a + 2, cmp);
sort(a, a + 2, item_cmp());
cout << a[0].x << " " << a[0].y << endl;
}