Compilare: main.cpp: In function 'int main()': main.cpp:31:23: warning: suggest parentheses around '&&' within '||' [-Wparentheses] if (c && c < M[i][j] || M[i][j] == 0) { ~~^~~~~~~~~~~~~~ main.cpp:9:24: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &n); ^ main.cpp:16:38: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &M[i][j]); ^