delete pics to save space

1.3807.cpp

@@ -0,0 +1,24 @@
+#include<cstdio>
+const int maxsize=100005;
+int k,n,m,p;
+long long inv_fac[maxsize],fac[maxsize];
+long long lucas(int x,int y)
+{
+    if(x<y) return 0;
+    else if(x<p) return fac[x]*inv_fac[y]*inv_fac[x-y]%p;
+    else return lucas(x/p,y/p)*lucas(x%p,y%p)%p;
+}
+int main()
+{
+    scanf("%d",&k);
+    while(k-->0)
+    {
+        scanf("%d%d%d",&n,&m,&p);
+        inv_fac[0]=inv_fac[1]=fac[0]=fac[1]=1;
+        for(int i=2;i<=n+m;i++) fac[i]=fac[i-1]*i%p;
+        for(int i=2;i<=n+m;i++) inv_fac[i]=(p-p/i)*inv_fac[p%i]%p;
+        for(int i=2;i<=n+m;i++) inv_fac[i]=inv_fac[i-1]*inv_fac[i]%p;
+        printf("%lld\n",lucas(n+m,m));
+    }
+    return 0;
+}