Another way of NYOJ 208

NYOJ/208_2.cpp

@@ -0,0 +1,68 @@
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <algorithm>
+using namespace std;
+#define MAXN 10005
+
+struct pack
+{
+    int profit,deadline;
+};
+
+pack p[MAXN];
+
+int father[MAXN];
+
+bool cmp(const pack& a,const pack& b)
+{
+    return a.profit>b.profit;
+}
+
+int GetFather(int pos)
+{
+    if(father[pos]==-1)
+    {
+        /// This pos is itself's father
+        return pos;
+    }
+    /// Else , this pos has a father. So it should know who is his Eldest Father.
+    father[pos]=GetFather(father[pos]);
+    /// And then , report back to it's caller.
+    return father[pos];
+}
+
+int main()
+{
+    int t;
+    while(scanf("%d",&t)==1)
+    {
+        /// Reset father
+        /** This way caused TLE.
+        for(int i=0;i<t;i++)
+        {
+            father[i]=i;
+        }
+        */
+        memset(father,-1,sizeof(int)*MAXN);
+        for(int i=0;i<t;i++)
+        {
+            scanf("%d %d",&p[i].profit,&p[i].deadline);
+        }
+        sort(p,p+t,cmp);
+        int sum=0;
+        for(int i=0;i<t;i++)
+        {
+            int ans=GetFather(p[i].deadline);
+            if(ans>0)
+            {
+                /// This pos's father is not 0 : which means it's possible to sell this thing.
+                sum+=p[i].profit;
+                /// And This pos become a son of the pos on its left.
+                father[ans]=GetFather(ans-1);
+            }
+        }
+        printf("%d\n",sum);
+    }
+    return 0;
+}