Create 3555_UESTC_Sayakiss.cpp

From http://acm.hdu.edu.cn/discuss/problem/post/reply.php?postid=1366&messageid=1&deep=0

HDOJ/3555_UESTC_Sayakiss.cpp

@@ -0,0 +1,77 @@
+#include<cstdio>
+#include<cmath>
+unsigned long long n,ans,sa,nn,np,t,f,i,c[30][30],k,f49;
+int fbreak,tcase;
+void cc()
+{
+    int i,j;
+    c[0][0]=1;
+    c[1][0]=1;c[1][1]=1;
+    for (i=0;i<25;i++)
+    {
+        c[i][0]=1;
+        for (j=1;j<=i;j++) c[i][j]=c[i-1][j]+c[i-1][j-1];
+    }
+}
+unsigned long long sayacal(long long n,int k)//10^n
+{
+    unsigned long long ans;
+    sa=1;f=1;ans=0;
+    while (1)
+    {        
+        sa++;k=k-2;n=n/100;if (n==0) break;
+        if (f) 
+        {
+            ans=ans+c[sa+k-1][k]*n;
+            f=0;
+        }
+        else
+        {
+            ans=ans-c[sa+k-1][k]*n;
+            f=1;
+        }
+    }
+    return ans;
+}
+    
+int main()
+{
+    cc();//计算组合数
+    scanf("%d",&tcase);
+    while(tcase--)
+    {
+        scanf("%I64d",&n);
+        if (n<49) {printf("0n");continue;}
+        ans=0;fbreak=0;
+        while (n)
+        {
+            k=0;nn=1;
+            while(nn<n)
+            {
+                nn=nn*10;
+                k++;
+            }
+            if (nn!=n) {nn=nn/10;k--;}
+            np=nn;unsigned nnp=0;
+            while (np<=n)
+            {
+                if (nnp!=4) ans+=sayacal(nn,k);
+                else 
+                {
+                    ans+=nn/10+sayacal(nn,k);
+                    ans-=sayacal(nn/10,k-1);
+                }
+                np+=nn;
+                nnp++;
+                if (nnp==4) f49=1; else f49=0;
+            }
+            n=n%nn;nn=nn/10;if (fbreak) break;
+            if (nn) if (f49) if ((n/nn)>8)
+            {
+                ans+=n%nn+1;
+                fbreak=1;
+            }
+        }
+        printf("%I64dn",ans);
+    }
+}