Binary search: basically eliminate the impossible elements by half each time by exploiting the sorted property.

```
int findMin(vector<int> &num) {
int lo =0, hi = num.size()-1;
while(lo<hi){
int mid=(lo+hi)/2;
if(num[mid]>num[hi]) lo=mid+1;
else hi=mid;
}
return num[lo];
}
```