Compilare: user.cpp: In function ‘void roy_floyd()’: user.cpp:26:113: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if (i != j && j != k && ((!C[i][j] || C[i][k] + C[k][j] < C[i][j]) || C[i][k] + C[k][j] == C[i][j] && tata[i][k]+tata[k][j]>tata[i][j])) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘void read()’: user.cpp:9:20: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^ user.cpp:13:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&C[i][j]); ^