Compilare: user.cpp: In function ‘int main()’: user.cpp:102:219: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while( ( ( a[i + 1][n3] - a[i + 1][n3 - 1] ) < ( a[j + 1][n2] - a[j + 1][n2 - 1] ) && n2 > 0 ) || ( ( a[i + 1][n3] - a[i + 1][n3 - 1] ) < ( a[i - 1][n1] - a[i - 1][n1 - 1] ) && n1 > 0 ) && n3 <= m ){ ^ user.cpp:171:219: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while( ( ( a[i + 1][n3] - a[i + 1][n3 - 1] ) < ( a[j + 1][n2] - a[j + 1][n2 - 1] ) && n2 > 0 ) || ( ( a[i + 1][n3] - a[i + 1][n3 - 1] ) < ( a[i - 1][n1] - a[i - 1][n1 - 1] ) && n1 > 0 ) && n3 <= m ){ ^ user.cpp:13:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d", &op ); ^ user.cpp:14:48: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d%d%d%d", &n, &m, &k1, &k2 ); ^ user.cpp:17:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d", &a[j][i] ); ^