Compilare: user.c: In function ‘HugeMultiply’: user.c:4:1: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration] memset(C,0,sizeof(C)); ^ user.c:4:1: warning: incompatible implicit declaration of built-in function ‘memset’ [enabled by default] user.c:8:1: warning: implicit declaration of function ‘memcpy’ [-Wimplicit-function-declaration] memcpy(A,C,sizeof(C));} ^ user.c:8:1: warning: incompatible implicit declaration of built-in function ‘memcpy’ [enabled by default] user.c: In function ‘main’: user.c:25:1: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration] l1=strlen(chA);l2=strlen(chB);A[0]=l1;B[0]=l2;a=b=0; ^ user.c:25:4: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default] l1=strlen(chA);l2=strlen(chB);A[0]=l1;B[0]=l2;a=b=0; ^ user.c:15:24: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] for(i=0;i<9;i++){fscanf(f,"%d",&fr[i]);sum+=fr[i];} ^