Compilare: user.cpp: In function ‘int main()’: user.cpp:56:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<l; j++) ^ user.cpp:65:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<l; j++) { ^ user.cpp:16:18: warning: unused variable ‘k’ [-Wunused-variable] unsigned int k=0, n, m, i, nr; ^ user.cpp:17:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%u %u %u\n", &n, &m, &l); ^ user.cpp:29:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%c", &a[i]); ^ user.cpp:39:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%c", &a[i]); ^ user.cpp:63:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "\n"); ^ user.cpp:66:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%c", &c); ^