Compilare: user.cpp: In function ‘void solveone()’: user.cpp:11:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); ++i) ~~^~~~~~~~~~ user.cpp:14:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 1; j <= k && i+j-1 < s.size(); ++j) ~~~~~~^~~~~~~~~~ user.cpp: In function ‘void solvetwo()’: user.cpp:37:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); ++i) ~~^~~~~~~~~~ user.cpp:40:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 1; j <= k && i+j-1 < s.size(); ++j) ~~~~~~^~~~~~~~~~ user.cpp:56:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i-1; j < s.size(); ++j) ~~^~~~~~~~~~