Compilare: main.cpp: In function 'int main()': main.cpp:50:12: warning: unused variable 'j' [-Wunused-variable] int i, j; ^ main.cpp:53:33: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &N, &M); ^ main.cpp:55:44: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d %d", &x, &y, &c); ^