题解 | #活动安排#

import sys
n = int(input())
tasks = []
for _ in range(n):
    a,b = map(int,input().split())
    tasks.append([b,a])
tasks.sort()
end = 0
count = 0
for i in range(n):
    b,a = tasks[i]
    if a>=end:
        end = b
        count += 1
print(count)

贪心算法

按结束时间排序