HDU 4883 TIANKENG's restaurant (interval selection)
HDU 4883 TIANKENG's restaurant
Question Link
Question: given some time as the interval, and a person in number, ask how many people to arrange (one person can only take care of one person)
Train of Thought: for the common interval point selection problem, split one interval into one entry point and one exit point, and then sort and cyclically find the answer.
Code:
#include
#include
#include using namespace std;const int N = 20005;struct Man { int v, t; Man() {} Man(int v, int t) {this->v = v; this->t = t;}} m[N];bool cmp(Man a, Man b) { if (a.t != b.t)return a.t < b.t; return a.v < b.v;}int n, t, mn;int main() { scanf("%d", &t); while (t--) {mn = 0;scanf("%d", &n);for (int i = 0; i < n; i++) { int a, b, c, d, e; scanf("%d%d:%d%d:%d", &a, &b, &c, &d, &e); int t1 = b * 60 + c; int t2 = d * 60 + e; m[mn++] = Man(a, t1); m[mn++] = Man(-a, t2);}sort(m, m + mn, cmp);int ans = 0, sum = 0;for (int i = 0; i < mn; i++) { sum += m[i].v; ans = max(ans, sum);}printf("%d\n", ans); } return 0;}