擦除vector中的所有元素，直到第一个非零元素C ++

Question

I have a vector that will store a variable number of zero elements at its beginning. These need to be erased.

I have tried:

while(v.at(0) == 0)
{
    v.erase(v.begin());
}

But this throws out an std::out_of_range error.

Any assistance would be appreciated.

Answer 1

You can use std::find_if to find the first non-zero value and then erase those elements:

auto first_non_zero = std::find_if(begin(v), end(v), [](int n){ return n != 0; });
v.erase(begin(v), first_non_zero);

( live demo )