算法1
思路:二分模板练习
C++ 代码
#include<iostream>
using namespace std;
const int N=100010;
int n,m;
int q[N];
int main(){
scanf("%d%d",&n,&m);
for(int i=0;i<n;i++) scanf("%d",&q[i]);
while(m--){
int x;
scanf("%d",&x);
int l=0,r=n-1;
while(l<r){
int mid=l+r>>1;
if(q[mid]>=x) r=mid;
else l=mid+1;
}
if(q[l]!=x) cout<<"-1 -1"<<endl;
else{
cout<<l<<' ';
int l=0,r=n-1;
while(l<r){
int mid=l+r+1>>1;
if(q[mid]<=x) l=mid;
else r=mid-1;
}
cout<<l<<endl;
}
}
return 0;
}