nyoj24 大数阶乘
链接:http://acm.nyist.net/JudgeOnline/problem.PHP?pid=28
正确代码:
#include<stdio.h> #include<string.h> #include<stdlib.h> #include<math.h> #include<algorithm> using namespace std; const int maxn=40000; int a[maxn]={0}; int main() { int m,i,j; scanf("%d",&m); a[0]=1; for(i=2;i<=m;i++) { int carry=0; for(j=0;j<maxn;j++) { int res=a[j]*i+carry; a[j]=res%10; carry=res/10; } } for(j=maxn-1;j>=0;j--) if(a[j]) break; for(i=j;i>=0;i--) printf("%d",a[i]); printf("\n"); return 0; } 超时代码: #include<stdio.h> #include<string.h> #include<stdlib.h> #include<math.h> #include<algorithm> using namespace std; char s[100000]; int main() { int m,&m); strcpy(s,"1"); for(i=2;i<=m;i++) { int carry=0; for(j=0;j<strlen(s);j++) { int res=(s[j]-'0')*i+carry; carry=res/10; s[j]=(res%10)+'0'; } while(carry!=0) { s[j++]=(carry%10)+'0'; carry/=10; } } reverse(s,s+strlen(s)); printf("%s\n",s); return 0; }