笔试-C笔1

j_ int 0 /* , */\rd {int x;.\rd x=fact(n)/fact®*fact(n-r);\rd /* x=fact(n)/(fact®*fact(n-r)); */\rd return(x);}\rd fact(int n)\rd {if(n=l)return 1;/* n==Olln==l */\rd else return(n*(n-l)); /*n*fact(n-l) */\rd )\rV WÕ?Y\r ˆÖ×"ÔÈ\rd a(0),a(D,a(2),....a(19)\r ˆÖ×"%L\rd a(0)=0;a(l)=l;a(2)=l;\rd a(n)=a(n-3)+2a(n-2)+a(n-l)\rd #include<stdio.h>\rd main()\rd {FILE *fp;long int a[20];int j;\rd if((fp=fopen(umyf2.out,,,,,w,,))==NULL)\rd {printf(uCan not open the file myf2.out!\n:);exit(l);)\rd a[0]=0;a[l]=l;a[2]=l;\rd for0=3;j<20;j++)\rd aUl=aU-3]+ 2*a[j-2]+aU-l];\rd for0=0;j<20;j++)\rd {fprintf(fp ,%121d,,,a[j]);\rd if(j+l)%4==0)fprintf(fp,,,\nM);\rd )\rd fclose(fp);