Compilare: main.cpp: In function 'int main()': main.cpp:18:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<expr.size();i++) ~^~~~~~~~~~~~ main.cpp:38:13: warning: this 'if' clause does not guard... [-Wmisleading-indentation] if (expr[i-1]=='-') ^~ main.cpp:41:17: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if' cx = cx + semn*nrcrt; ^~