Create 1821_proverbs.cpp

From http://www.cnblogs.com/proverbs/archive/2012/10/04/2711751.html

POJ/1821_proverbs.cpp

@@ -0,0 +1,71 @@
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+#include <algorithm>
+#include <iostream>
+
+#define N 120
+#define M 17000
+
+using namespace std;
+
+struct RE
+{
+    int l,p,s;
+} re[N];
+
+int q[M],l[N],r[N],dp[N][17000],n,k;
+
+inline bool cmp(const RE &a,const RE &b)
+{
+    return a.s<b.s;
+}
+
+void read()
+{
+    for(int i=1; i<=k; i++)
+        scanf("%d%d%d",&re[i].l,&re[i].p,&re[i].s);
+    sort(re+1,re+1+k,cmp);
+
+    for(int i=1; i<=k; i++)
+    {
+        l[i]=max(0,re[i].s-re[i].l);
+        r[i]=min(n,re[i].s+re[i].l-1);
+    }
+}
+
+void go()
+{
+    for(int i=0; i<=n; i++) dp[0][i]=0;
+    for(int i=1; i<=k; i++)
+    {
+        for(int j=0; j<re[i].s; j++) dp[i][j]=dp[i-1][j]; //第i个粉刷匠不刷任何墙
+        int h=0,t=0;
+        for(int j=l[i],tmp; j<re[i].s; j++) //将dp[i-1]层的最优状态存入单调队列
+        {
+            tmp=dp[i-1][j]-j*re[i].p;
+            while(t>h&&dp[i-1][q[t-1]]-q[t-1]*re[i].p<=tmp) t--;
+            q[t++]=j;
+        }
+        for(int j=re[i].s,tmp; j<=r[i]; j++)
+        {
+            while(t>h&&j-q[h]>re[i].l) h++;//弹出不在范围中的元素
+            dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
+            dp[i][j]=max(dp[i][j],dp[i-1][q[h]]+(j-q[h])*re[i].p);
+        }
+        for(int j=r[i]+1; j<=n; j++) dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
+    }
+    int ans=0;
+    for(int i=1; i<=n; i++) ans=max(ans,dp[k][i]);
+    printf("%d\n",ans);
+}
+
+int main()
+{
+    while(scanf("%d%d",&n,&k)!=EOF)
+    {
+        read();
+        go();
+    }
+    return 0;
+}