自定义sort升序降序的方法如下
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include<iostream> #include<algorithm> #include<cstdio> using namespace std; struct period { int st; int end; }; int read() { int x=0,f=1; char ch=getchar(); while(ch<'0'||ch>'9') { if(ch=='-') f=-1; ch=getchar(); } while(ch>='0'&&ch<='9') { x=x*10+ch-'0'; ch=getchar(); } return x*f; } bool cmp(period x,period y) //升序排列 { return x.end<y.end; } int main() { int a; int temp,ans=1; a=read(); period n[a]; for(int i=0;i<a;i++) { n[i].st=read(); n[i].end=read(); } sort(n,n+a,cmp); temp=n[0].end; for(int i=1;i<a;i++) if(n[i].st>=temp) { temp=n[i].end; ans++; } cout<<ans; return 0; }