foo.cc: In function 'void solve()':
foo.cc:29:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
29 | for(int i = 0; i < v.size(); ++i)
| ~~^~~~~~~~~~
foo.cc:31:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
31 | for(int i = 0; i < v.size(); ++i) {
| ~~^~~~~~~~~~
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