8.15B题笔记

8.15/B-House Man/Readme.md

@@ -1,12 +1,17 @@
-# ﾌ籠ｿ
+# B - House Man
-* ﾁｴｽﾓ
+* https://vjudge.net/contest/509525#problem/B
 ### 题意
-
+给定有一定顺序的一组数，要求从小到大走，最大跨D这么远即A到B中间最多隔着（D-1）个，问能否走到，最小和最大的最大距离多少
 ### 做法
-
+差分约束（1.原来顺序左到右>=1;2.小到大再按原来的左到右<=D）
+max,min中原来id小的做S,id大的做T;dist[T]就是答案
 ### 关键词
-
+差分约束，构图，源点，汇点
 ### 易错点
-
+构图，还是不是很理解
+//TLE 判断负环的(been/times)放错位置
+cnt=0;//WA罪魁祸首! 没有每次赋零
+scanf("%d",&a[i].h);//怎么总是你&！！ 
+ wa=0;//WA？ bool标记忘了每次赋零 
 ### 工具箱
 * 

8.15/F - Candies.cpp

@@ -1,70 +0,0 @@
-//youwu
-#include <iostream>
-#include<cstdio>
-#include<algorithm>
-#include<cstring>
-#include<stack>
-using namespace std;
-const int N=3e4+5,N3=15e4+5,inf=0x3f3f3f3f;
-int to[N3],ne[N3],w[N3],h[N],cnt=0,s=N-4,e,dist[N];
-bool in[N],wa=0,u,v,w1;
-int n,m,maxn=0;
-void add(int u,int v,int w1)
-{
-    to[++cnt]=v;
-    ne[cnt]=h[u];
-    w[cnt]=w1;
-    h[u]=cnt;
-}
-void spfa()
-{
-	stack<int>q;//queue没有自带函数清零 
-	q.push(s);
-	while(!q.empty())
-	{
-		int u=q.top();
-		q.pop();
-		in[u]=0;//spfa的精髓！！ 
-		for(int i=h[u];i;i=ne[i])
-		{
-			int v=to[i],w1=w[i];
-//			printf("%d %d %d\n",u,v,w1);
-			if(dist[u]+w1<dist[v])
-			{
-				dist[v]=dist[u]+w1;
-//			printf("%d(%d) %d(%d) %d\n",u,dist[u],v,dist[v],w1);
-				if(!in[v])
-				{
-					q.push(v);
-					in[v]=1;
-				}
-			}
-		}
-	}
-}
-int main()
-{
-        scanf("%d%d",&n,&m);
-        for(int  i=0;i<=n;i++)
-        {
-            dist[i]=inf;
-        }
-        for(int i=1;i<=m;i++)//n,m不分 
-        {
-            scanf("%d%d%d",&u,&v,&w1); 
-            add(u,v,w1);
-        }
-        s=1;
-        dist[s]=0;
-        spfa();
-        maxn=0;
-//        for(int i=2;i<=n;i++)
-//        {
-//        	if(dist[i]>maxn)
-//        	{
-//        		maxn=dist[i];
-//			}
-//		}
-        printf("%d",dist[n]);
-    return 0;
-}

8.15/F-Candies/doc/Readme.md

@@ -0,0 +1 @@
+# 

8.15/F-Candies/main.cpp

@@ -0,0 +1,70 @@
+#include <iostream>
+#include <cstdio>
+#include <algorithm>
+#include <cstring>
+#include <stack>
+using namespace std;
+const int N = 3e4 + 5, N3 = 15e4 + 5, inf = 0x3f3f3f3f;
+int to[N3], ne[N3], w[N3], h[N], cnt = 0, s = N - 4, e, dist[N];
+bool in[N], wa = 0;
+int  u, v, w1;//WA 和bool放一起了
+int n, m, maxn = 0;
+void add(int u, int v, int w1)
+{
+	to[++cnt] = v;
+	ne[cnt] = h[u];
+	w[cnt] = w1;
+	h[u] = cnt;
+}
+void spfa(int s)
+{
+	memset(dist,0x3f,sizeof dist);//更好的賦初值方法
+	dist[s] = 0;//和賦inf顺序反了=白干
+	stack<int> q; // queue没有自带函数清零
+	q.push(s);
+	while (!q.empty())
+	{
+		u = q.top();
+		q.pop();
+		in[u] = 0; // spfa的精髓！！
+		for (int i = h[u]; i; i = ne[i])
+		{
+			v = to[i], w1 = w[i];
+			//			printf("%d %d %d\n",u,v,w1);
+			if (dist[u] + w1 < dist[v])
+			{
+				dist[v] = dist[u] + w1;
+				//			printf("%d(%d) %d(%d) %d\n",u,dist[u],v,dist[v],w1);
+				if (!in[v])
+				{
+					q.push(v);
+					in[v] = 1;
+				}
+			}
+		}
+	}
+}
+int main()
+{
+	scanf("%d%d", &n, &m);
+	// for (int i = 0; i <= n; i++)
+	// {
+	// 	dist[i] = inf;
+	// }
+	for (int i = 1; i <= m; i++) // n,m不分
+	{
+		scanf("%d%d%d", &u, &v, &w1);
+		add(u, v, w1);
+	}
+	spfa(1);
+	// maxn = 0;
+	//        for(int i=2;i<=n;i++)
+	//        {
+	//        	if(dist[i]>maxn)
+	//        	{
+	//        		maxn=dist[i];
+	//			}
+	//		}
+	printf("%d", dist[n]);
+	return 0;
+}

8.15/F-Candies/reference.cpp

@@ -0,0 +1,80 @@
+#include <iostream>
+#include <cstring>
+#include <algorithm>
+#include <stack>
+using namespace std;
+
+typedef long long LL;
+typedef pair<int, int> PII;
+const int INF = 0x3f3f3f3f;
+
+const int N = 30005, M = 150005;
+
+inline int read()
+{
+    register int x = 0, f = 1;
+    register char ch = getchar();
+    while(ch < '0' || ch > '9')
+    {
+        if(ch == '-') f = -1;
+        ch = getchar();
+    }
+    while(ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
+    return x * f;
+}
+
+int n, m;
+struct Edge
+{
+    int v,nxt,w;
+}e[M];
+int head[N], idx = 0;
+inline void add(int u,int v,int w=0)
+{
+    e[++idx].v = v,e[idx].w = w, e[idx].nxt = head[u],head[u] = idx;
+}
+
+int dis[N], st[N], times[N]; 
+bool spfa(int start)
+{
+    stack<int> q;
+    memset(dis,0x3f,sizeof dis);
+    dis[start] = 0, st[start] = times[start] = 1, q.push(start);
+
+    while(!q.empty())
+    {
+        int u = q.top(); q.pop();
+
+        st[u] = 0;
+        for(int i=head[u];i;i=e[i].nxt)
+        {
+            int v = e[i].v, w = e[i].w;
+            if(dis[v] > dis[u] + w)
+            {
+                dis[v] = dis[u] + w;
+                if(!st[v]) 
+                {
+                    st[v] = 1, q.push(v);
+                    // if(times[v] >= n) return 0;
+                }
+            }
+        }
+    }
+
+    return 1; 
+}
+
+int main()
+{
+    n = read(), m = read();
+    for(int i=1;i<=m;i++)
+    {
+        int u = read(),v = read(),w = read();
+        add(u,v,w);
+    } 
+
+    spfa(1);
+    cout<<dis[n]<<endl;
+
+    return 0;
+}

8.15/F-Candies/test/out.txt

@@ -0,0 +1,7 @@
+## z:\Chao\src\Template\test\in.txt 
+2020/03/14 ÖÜÁù 11:41:28.68 
+Hello Easy C++ project!
+
+-----------------------------------------------
+Process exited after 200 ms with return value 0
+

Template/Readme.md

@@ -7,6 +7,6 @@
 ### 关键词
 
 ### 易错点
-
+* 
 ### 工具箱
 *