delete pics to save space

2.10288.cpp

@@ -0,0 +1,64 @@
+#include<iostream>
+#include<sstream>
+using namespace std;
+typedef long long LL;
+LL gcd(LL a, LL b)
+{
+    return !b?a:gcd(b,a%b);
+}
+inline LL lcm(LL a, LL b)
+{
+    return a/gcd(a,b)*b;
+}
+inline int len(LL x)
+{
+    stringstream ss;
+    ss<<x;
+    return ss.str().length();
+}
+inline void print_chars(int cnt,char ch)
+{
+    while(cnt--) cout << ch;
+}
+inline void output(LL a,LL b,LL c)
+{
+    if(b==0) cout<<a<<"\n";
+    else
+    {
+        int L1=len(a);
+        print_chars(L1+1,' ');
+        cout<<b<<"\n";
+        cout<<a<<" ";
+        print_chars(len(c),'-');
+        cout<<"\n";
+        print_chars(L1+1,' ');
+        cout<<c<<"\n";
+    }
+}
+int n,i;
+LL x,a,b,c,g;
+int main()
+{
+#ifdef local
+    freopen("pro.in","r",stdin);
+#endif
+    while(cin>>n&&n)
+    {
+        if(n==1) {output(1,0,0); continue;}
+        x=1;
+        for(i=2;i<=n-1;i++)
+            x=lcm(x, i);
+        //b/c = 1/(n-1) + ... + 1/2
+        c=x,b=0;
+        for(i=2;i<=n-1;i++)
+            b+=x/i;
+        b*=n;
+        g=gcd(b,c);
+        b/=g;
+        c/=g;
+        //ans = a + b/c
+        a=1+n+b/c;
+        output(a,b%c,c);
+    }
+    return 0;
+}