Compilare: main.cpp: In function 'int main()': main.cpp:33:37: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d%d", &n, &m, &len); ^ main.cpp:37:34: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &ma[i][j]); ^