Compilare: main.cpp: In function 'void btr(int)': main.cpp:20:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < I.size(); i++){ ~~^~~~~~~~~~ main.cpp:27:58: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] int j = v[nl][nc] - 1, flag = (i == I.size() - 1); ~~^~~~~~~~~~~~~~~ main.cpp:27:48: warning: unused variable 'flag' [-Wunused-variable] int j = v[nl][nc] - 1, flag = (i == I.size() - 1); ^~~~ main.cpp: In function 'int main()': main.cpp:47:36: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d%d", &n, &m, &i); ^ main.cpp:50:34: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d", &l, &c); ^