Compilare: user.cpp: In function ‘void solveone()’: user.cpp:10:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); ++i) ~~^~~~~~~~~~ user.cpp:13:40: 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:39:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); ++i) ~~^~~~~~~~~~ user.cpp:42:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 1; j <= k && i+j-1 < s.size(); ++j) ~~~~~~^~~~~~~~~~ user.cpp:55:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < s.size(); ++j) ~~^~~~~~~~~~ user.cpp:68:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i-1; j < s.size(); ++j) ~~^~~~~~~~~~