Create 2373_sunny606_无优化.cpp

From http://blog.csdn.net/sunny606/article/details/7854362

POJ/2373_sunny606_无优化.cpp

@@ -0,0 +1,84 @@
+#include<cstdio>
+#include<cstring>
+#define L 1001000
+
+int a,b,n,l,inf,dp[L];
+int tree[4*L];
+
+void updata(int *p, int rt, int l, int r,int pos, int k)
+{
+     if (l==r) {
+          p[rt]=k;
+          return ;
+     }
+     int mid=(l+r)>>1;
+     if (pos<=mid) updata(p,rt<<1, l, mid, pos, k);
+     else updata(p, rt<<1|1, mid+1, r, pos, k);
+     int lv=p[rt<<1];
+     int rv=p[rt<<1|1];
+     p[rt]=lv<rv?lv:rv;
+}
+
+int query(int *p,int rt, int l,int r, int s, int e)
+{
+    if(l==s && e==r) return p[rt];
+    int mid = (l+r)>>1;
+    if(e<=mid) return query(p, rt<<1, l, mid, s, e);
+    if(s>mid) return query(p, rt<<1|1, mid+1, r, s, e);
+    int lv=query(p,rt<<1, l, mid, s,mid);
+    int rv=query(p,rt<<1|1, mid+1, r, mid+1, e);
+    return lv<rv?lv:rv;
+}
+
+int dpro(void)
+{
+     if(b<1) return -1;
+     dp[0]=0;
+
+     for(int j=0; j<4*L; j++) tree[j]=L*2;
+
+     for(int j=a; j<=b; j++){
+         if(dp[2*j]<=inf) dp[0+2*j] = dp[0]+1;
+         updata(tree,1, 1, l ,j,dp[2*j]);
+     }
+     
+     for(int i=2*b+2; i<=l; i+=2)
+     {
+         int min;
+         int pos = (i>>1);
+         min = query(tree, 1, 1, l, pos-b, pos-a);
+
+         if (dp[i]<=inf) {
+              //if(dp[i]>min+1) 
+              dp[i]=min+1;
+              updata(tree,1,1,l,pos,dp[i]);
+                     /*for(int j=a; j<=b; j++) {
+                         int idx = i-2*j;
+                         if(idx<0) break;
+                         if ( dp[i]>dp[idx]+1 ) dp[i]=dp[idx]+1;
+                     }*/
+         }
+     }
+     if(dp[l]>=inf) return -1;
+     else return dp[l];
+}
+
+int main()
+{
+    while (scanf("%d%d", &n, &l)!=EOF) {
+
+          scanf("%d%d", &a, &b);
+          inf = (l/a)+9;
+          for(int i=0; i<=l; i++) dp[i]=inf;
+
+          for(int i=0; i<n; i++) {
+                int s, e;  
+                scanf("%d%d", &s, &e);
+                for(int j=s+1; j<e; j++) dp[j] = inf+1;
+          }
+
+          if(l&1==1) printf("-1\n");
+          printf("%d\n", dpro());
+    }
+    return 0;
+}