2020牛客寒假算法基础集训营4-I 匹配星星【贪心】

 

 链接：https://ac.nowcoder.com/acm/contest/3005/I
来源：牛客网

示例1

输入

复制 
2
1 1 0
2 2 1

输出

复制 
1
示例2

输入

复制 
2
1 1 1
2 2 1

输出

复制 
0

备注:

 

 思路：

　　

 

 

 

  1 #include <bits/stdc++.h>
  2 #define dbg(x) cout << #x << "=" << x << endl
  3 
  4 using namespace std;
  5 typedef long long LL;
  6 
  7 template<class T>inline void read(T &res)
  8 {
  9     char c;T flag=1;
 10     while((c=getchar())<'0'||c>'9')if(c=='-')flag=-1;res=c-'0';
 11     while((c=getchar())>='0'&&c<='9')res=res*10+c-'0';res*=flag;
 12 }
 13 
 14 namespace _buff {
 15     const size_t BUFF = 1 << 19;
 16     char ibuf[BUFF], *ib = ibuf, *ie = ibuf;
 17     char getc() {
 18         if (ib == ie) {
 19             ib = ibuf;
 20             ie = ibuf + fread(ibuf, 1, BUFF, stdin);
 21         }
 22         return ib == ie ? -1 : *ib++;
 23     }
 24 }
 25 
 26 int qread() {
 27     using namespace _buff;
 28     int ret = 0;
 29     bool pos = true;
 30     char c = getc();
 31     for (; (c < '0' || c > '9') && c != '-'; c = getc()) {
 32         assert(~c);
 33     }
 34     if (c == '-') {
 35         pos = false;
 36         c = getc();
 37     }
 38     for (; c >= '0' && c <= '9'; c = getc()) {
 39         ret = (ret << 3) + (ret << 1) + (c ^ 48);
 40     }
 41     return pos ? ret : -ret;
 42 }
 43 
 44 const int maxn = 1e5 + 7;
 45 
 46 set <int> s;
 47 map<int, int> mapp;
 48 
 49 int n;
 50 
 51 struct node {
 52     int x,y,z;
 53 }a[maxn];
 54 
 55 bool cmp(node a, node b) {
 56     if(a.x == b.x) {
 57         return a.z > b.z;
 58     }
 59     return a.x < b.x;
 60 }
 61 
 62 int main()
 63 {
 64     read(n);
 65     for(int i = 1; i <= n; ++i) {
 66         scanf("%d %d %d",&a[i].x, &a[i].y, &a[i].z);
 67     }
 68     sort(a+1, a+n+1, cmp);
 69     set<int>::iterator it;
 70 
 71     LL ans = 0;
 72     for(int i = 1; i <= n; ++i) {
 73         if(a[i].z == 0) {
 74             if(!mapp[a[i].y]) {
 75                 s.insert(a[i].y);
 76             }
 77             mapp[a[i].y]++;
 78         }
 79         if(a[i].z == 1) {
 80             it = s.lower_bound(a[i].y);
 81             if(it != s.begin()) {
 82                 mapp[*it]--;
 83                 if(!mapp[*it]) {
 84                     s.erase(*it);
 85                 }
 86                 dbg(*it);
 87                 ans++;
 88             }
 89         }
 90     }
 91     cout << ans << endl;
 92     return 0;
 93 }
 94 /*
 95 5
 96 1 1 0
 97 2 2 0
 98 3 3 0
 99 4 4 0
100 5 5 1
101 */
View Code

 


posted @ 2020-02-11 23:39  Orangeko  阅读(282)  评论(0)  编辑  收藏  举报