Compilare: main.cpp:38:19: warning: multi-character character constant [-Wmultichar] else g << '-1'; ^~~~ main.cpp: In function 'int main()': main.cpp:12:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation] for (j = 0 ; j < M ; j ++) ^~~ main.cpp:15:9: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for' subsirB = b.substr(0,j); ^~~~~~~