标签:style blog class code tar color
题目地址:http://pat.zju.edu.cn/contests/pat-a-practise/1076
此题考查图的遍历操作:
本来我个人觉得可以用dfs的,但是不知何故,有两个case没有过,贴出代码,望指出错误之处:
#include <cstdio> #include <map> #include <vector> #include <memory.h> using namespace std; const int NUM=1001; bool visited[NUM]; int forwards; map<int,vector<int> > adjlist; void reset() { memset(visited,false,sizeof(bool)*NUM); forwards=0; } void dfs(int sourceNode,int indLevel,int L) { if(indLevel>L) return; for(vector<int>::iterator iter=adjlist[sourceNode].begin();iter!=adjlist[sourceNode].end();++iter) { if(!visited[*iter]) { ++forwards; visited[*iter]=true; dfs(*iter,indLevel+1,L); } } } int _tmain(int argc, _TCHAR* argv[]) { int N,L; scanf("%d %d",&N,&L); if(L>6) L=6; int i,Mi,j,followed; for(i=1;i<=N;++i) { scanf("%d",&Mi); for(j=0;j<Mi;++j) { scanf("%d",&followed); adjlist[followed].push_back(i); } } int K,query; scanf("%d",&K); for(i=0;i<K;++i) { scanf("%d",&query); reset(); visited[query]=true; dfs(query,1,L); printf("%d\n",forwards); } return 0; }
后来换了bfs后,AC了:
#include <cstdio> #include <map> #include <vector> #include <queue> #include <memory.h> using namespace std; const int NUM=1001; bool hasForward[NUM]; int forwards; map<int,vector<int> > adjlist; queue<int> recordQueue; void reset() { memset(hasForward,false,sizeof(bool)*NUM); forwards=0; while(!recordQueue.empty()) recordQueue.pop(); } void bfs(int query,int level) { int curLevel=1; hasForward[query]=true; recordQueue.push(query); int endOfLevel=recordQueue.back(); int cur; while(!recordQueue.empty()&&curLevel<=level) { cur=recordQueue.front(); recordQueue.pop(); for(vector<int>::iterator iter=adjlist[cur].begin();iter!=adjlist[cur].end();++iter) { if(!hasForward[*iter]) { recordQueue.push(*iter); ++forwards; hasForward[*iter]=true; } } if(cur==endOfLevel) { ++curLevel; endOfLevel=recordQueue.back(); } } } int _tmain(int argc, _TCHAR* argv[]) { int N,L; scanf("%d %d",&N,&L); if(L>6) L=6; int i,j; int Mi,followed; for(i=1;i<=N;++i) { scanf("%d",&Mi); for(j=0;j<Mi;++j) { scanf("%d",&followed); adjlist[followed].push_back(i); } } int K,query; scanf("%d",&K); for(i=0;i<K;++i) { scanf("%d",&query); reset(); bfs(query,L); printf("%d\n",forwards); } return 0; }
PAT 1076. Forwards on Weibo (30),布布扣,bubuko.com
PAT 1076. Forwards on Weibo (30)
标签:style blog class code tar color
原文地址:http://www.cnblogs.com/wwblog/p/3709216.html