leetcode 924 solution

Author: fighter

leetcode/924.md

@@ -0,0 +1,63 @@
+
+**坑点**:
+
+1. 不是删除一个顶点，是将一个顶点去除颜色
+
+# 题目链接
+
+[minimize-malware-spread](https://leetcode.com/problems/minimize-malware-spread/)
+
+
+# 分析
+
+了解上面的坑点之后就简单多了
+
+只有当且仅当一个 initial 点在连通分量中，我们擦除它的颜色才有收益
+
+# code
+
+```java
+import java.util.*;
+class Solution {
+    public int minMalwareSpread(int[][] graph, int[] initial) {
+    	Arrays.sort(initial);
+    	int n = graph.length;
+    	int[] comp = new int[n];
+    	int[] candidate = new int[n+1];
+    	boolean[] isVal = new boolean[n];
+    	for(int i=0 ; i<initial.length ; ++i)isVal[initial[i]] = true;
+    	int C = 0;
+    	for(int i=0 ; i<graph.length ; ++i){
+    		Queue<Integer> Q = new LinkedList<>();
+    		if(comp[i]==0)dfs(i, ++C, comp, graph,Q,isVal);
+    		if(Q.size() == 1){
+    			candidate[C] = Q.remove()+1;
+    		}
+    	}
+    	
+    	int[] cnt = new int[C+1];
+    	for(int i=0 ; i<n ; ++i)cnt[comp[i]]++;
+    	int val = 0,ans = 0;
+    	for(int i=1 ; i <=C ; ++i)
+    		if(candidate[i]!=0){
+    			if(cnt[i] > val|| (cnt[i] == val && ans > candidate[i])){
+    				ans = candidate[i];
+    				val = cnt[i];
+    			}
+    		}
+    	
+    	if(ans !=0)return ans -1;
+    	else return initial[0];
+    		
+    }
+    private void dfs(int u, int col,int[] comp,int[][] g, Collection<Integer> black,boolean[] isVal) {
+		comp[u] = col;
+		if(isVal[u])black.add(u);
+		for(int i=0 ; i< comp.length ; ++i)
+			if(g[u][i]==1 &&comp[i]==0)dfs(i, col, comp,g,black,isVal);
+	}
+}
+
+```
+
+