题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5047
2 1 2
Case #1: 2 Case #2: 19
PS:
推出公式:8*n^2 - 7*n + 1 ,套一下模板就好了! 不过很多大数模板这题是会T的,不过这个模板:http://blog.csdn.net/u012860063/article/details/39612037 多亏了队友的神模板2333333!
代码如下:
#include <cstdio> #include <cstring> #include <malloc.h> /*大数加法*/ void add(char* a,char* b,char* c) { int i,j,k,max,min,n,temp; char *s,*pmax,*pmin; max=strlen(a); min=strlen(b); if (max<min) { temp=max; max=min; min=temp; pmax=b; pmin=a; } else { pmax=a; pmin=b; } s=(char*)malloc(sizeof(char)*(max+1)); s[0]='0'; for (i=min-1,j=max-1,k=max; i>=0; i--,j--,k--) s[k]=pmin[i]-'0'+pmax[j]; for (; j>=0; j--,k--) s[k]=pmax[j]; for (i=max; i>=0; i--) if (s[i]>'9') { s[i]-=10; s[i-1]++; } if (s[0]=='0') { for (i=0; i<=max; i++) c[i-1]=s[i]; c[i-1]='\0'; } else { for (i=0; i<=max; i++) c[i]=s[i]; c[i]='\0'; } free(s); } /*大数减法*/ void subtract(char* a,char* b,char* c) { int i,j,ca,cb; ca=strlen(a); cb=strlen(b); if (ca>cb||(ca==cb&&strcmp(a,b)>=0)) { for (i=ca-1,j=cb-1; j>=0; i--,j--) a[i]-=(b[j]-'0'); for (i=ca-1; i>=0; i--) if (a[i]<'0') { a[i]+=10; a[i-1]--; } i=0; while (a[i]=='0') i++; if (a[i]=='\0') { c[0]='0'; c[1]='\0'; } else { for (j=0; a[i]!='\0'; i++,j++) c[j]=a[i]; c[j]='\0'; } } else { for (i=ca-1,j=cb-1; i>=0; i--,j--) b[j]-=(a[i]-'0'); for (j=cb-1; j>=0; j--) if (b[j]<'0') { b[j]+=10; b[j-1]--; } j=0; while (b[j]=='0') j++; i=1; c[0]='-'; for (; b[j]!='\0'; i++,j++) c[i]=b[j]; c[i]='\0'; } } /* 大数乘法*/ void multiply(char* a,char* b,char* c) { int i,j,ca,cb,* s; ca=strlen(a); cb=strlen(b); s=(int*)malloc(sizeof(int)*(ca+cb)); for (i=0; i<ca+cb; i++) s[i]=0; for (i=0; i<ca; i++) for (j=0; j<cb; j++) s[i+j+1]+=(a[i]-'0')*(b[j]-'0'); for (i=ca+cb-1; i>=0; i--) if (s[i]>=10) { s[i-1]+=s[i]/10; s[i]%=10; } i=0; while (s[i]==0) i++; for (j=0; i<ca+cb; i++,j++) c[j]=s[i]+'0'; c[j]='\0'; free(s); } /*大数除法,返回余数*/ int dividor(char* a,int b,char* c) { int i,j,temp=0,n; char* s; n=strlen(a); s=(char*)malloc(sizeof(char)*(n+1)); for (i=0; a[i]!=0; i++) { temp=temp*10+a[i]-'0'; s[i]=temp/b+'0'; temp%=b; } s[i]='\0'; for (i=0; s[i]=='0'&&s[i]!='\0'; i++); if (s[i]=='\0') { c[0]='0'; c[1]='\0'; } else { for (j=0; s[i]!='\0'; i++,j++) c[j]=s[i]; c[j]='\0'; } free(s); return temp; } const int maxn = 1017; char s[maxn], t1[maxn], t2[maxn], t3[maxn]; char a[17], b[17], c[17]; char ans[maxn]; int main() { a[0] = '8'; a[1] = '\0'; b[0] = '7'; b[1] = '\0'; c[0] = '1'; c[1] = '\0'; int t; int cas = 0; scanf("%d",&t); getchar(); while(t--) { memset(ans,'\0',sizeof(ans)); gets(s); multiply(s,s,t1);//n^2 multiply(t1,a,t2);//8*n^2 multiply(b,s,t3);//7*n subtract(t2,t3,ans);//8*n^2 - 7*n add(ans,c,ans);//8*n^2 - 7*n + 1 printf("Case #%d: %s\n",++cas,ans); } return 0; } //8*n^2 - 7*n + 1
原文地址:http://blog.csdn.net/u012860063/article/details/39617811