Compilare: user.c: In function ‘main’: user.c:83:5: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration] memset(operand, 0, 20 * sizeof(long long)); ^ user.c:83:5: warning: incompatible implicit declaration of built-in function ‘memset’ [enabled by default] user.c:69:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &N); ^ user.c:72:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &A[i]); ^ user.c:75:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%lld", &B[i]); ^