g++ error: stray '\177' in program - c++

Question

I was trying to code for following program
Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).
You may assume that the intervals were initially sorted according to their start times.
Example 1:
Given intervals [1,3],[6,9] insert and merge [2,5] would result in [1,5],[6,9].
Example 2:
Given [1,2],[3,5],[6,7],[8,10],[12,16], insert and merge [4,9] would result in [1,2],[3,10],[12,16].
This is the relevant part of my program
here. I want to erase the few positions from the vector
then I am getting the following error
error: stray '\177' in program
intervals.erase(intervals.begin()+(p+1),intervals.begin()+(q+1));
vector<Interval> Solution::insert(vector<Interval> &intervals, Interval newInterval) {
int n = intervals.size();
int p=-1,q=-1,a,b;
for(int i=0;i<n;++i){
if(intervals[i].start <= newInterval.start <= intervals[i+1].end)
p = i;
else if(intervals[i].end < newInterval.start < intervals[i+1].start)
a = i;
if(intervals[i].start <= newInterval.end <= intervals[i+1].end)
q = i;
else if(intervals[i].end < newInterval.end < intervals[i+1].start)
b = i;
}
int x,z;
if(p != -1 && q != -1)
x = q-p;
if(x > 0){
z=intervals[q].end;
intervals.erase(intervals.begin()+(p+1),intervals.begin()+(q+1));
intervals[p].end = z;
}
return vector
}

Answer 1

Did you copy that code from a website?
I managed to reproduce your result with this snippet:
const char* msg = "You can't copy this";
When copied and put on coliru here you'll get the same error code.
What I used for the above snippet in HTML code was:
<code>const char* msg = </code><code>"You can't copy this";
</code>
Note the  character I put in there.
To fix that, you can use a decent editor like Notepad++ that will make the stray characters visible: