题目描述
算法1
Python代码
n = int(input())
arr = []
for _ in range(n):
l, r = map(int, input().split())
arr.append([l, r])
arr.sort()
ret = []
st, ed = arr[0]
for i in range(1, n):
if arr[i][0] > ed:
ret.append([st, ed])
st, ed = arr[i]
else:
ed = max(ed, arr[i][1])
print(len(ret) + 1)