Compilare: user.cpp: In function ‘int main()’: user.cpp:17:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<strlen(a);i++) { ^ user.cpp:19:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(a[j-1]*s>a[j]*s&&j<strlen(a)) {l++; s=s*-1; j++;} ^ user.cpp:28:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<strlen(a)) { ^ user.cpp:13:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%s",&p,a); ^