AcWing 789. 数的范围
原题链接
简单
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5+10;
int a[N];
int n,q;
int divid1(int q[],int l,int r,int c){
while(l < r){
int mid = l + r >> 1;
if(q[mid] >= c) r = mid;
else l = mid + 1;
}
if(q[l] == c) return l;
else return -1;
}
int divid2(int q[],int l,int r,int c){
while(l < r){
int mid = l + r + 1>> 1;
if(q[mid] <= c) l = mid;
else r = mid - 1;
}
return l;
}
int main(){
scanf("%d%d",&n,&q);
for(int i = 0 ; i < n ; i++) scanf("%d",&a[i]);
while(q--){
int k;
cin>>k;
int ans1 = divid1(a,0,n-1,k);
if(ans1 == -1){
printf("-1 -1\n");
}
else{
int ans2 = divid2(a,0,n-1,k);
printf("%d %d\n",ans1,ans2);
}
}
return 0;
}