Codeforces-1066B heaters.

  1 #include <cstdio>  2 #include <cstring>  3 #include <vector>  4 #include <iostream>  5 #include <algorithm>  6 #include <set>  7 #include <map>  8 #include <stack>  9  10 using namespace std; 11  12 #define _for(i,a,b) for(int i = (a);i < (b);i ++) 13 #define _rep(i,a,b) for(int i = (a);i <= (b);i ++) 14 typedef long long int ll; 15  16 struct cmp 17 { 18     inline bool operator() (const int a,const int b) 19     { 20         return a >= b; 21     } 22 }; 23  24 int readint() 25 { 26     int x;    //vector<int> v;v.push_back(readint()) 27     scanf("%d",&x); 28     return x; 29 } 30  31 struct edge 32 { 33     int Left; 34     int Right; 35 }; 36  37 int main() 38 { 39     int n,r; 40     while(~scanf("%d %d",&n,&r)) 41     { 42         vector<pair<int,int>> v; 43         int heaterNum = 0; 44         for(int i = 0;i < n;i ++) 45         { 46             int tmp; 47             scanf("%d",&tmp); 48             if(tmp) 49             { 50                 heaterNum ++; 51                 int left,right; 52                 left = i-r+1; 53                 right = i+r-1; 54                 if(i-r+1<0) 55                 { 56                     left = 0; 57                 } 58                 if(i+r-1>=n) 59                 { 60                     right = n-1; 61                 } 62                 v.push_back(make_pair(left,right)); 63             }  64         } 65          66         sort(v.begin(),v.end()); 67     //    for(auto p:v) 68     //        cout << p.first << " " << p.second << endl; 69         int test[n] {0}; 70         for(int i = 0;i < v.size();i ++) 71         { 72             for(int j = v[i].first;j <= v[i].second;j ++) 73                 test[j] = 1; 74         } 75         int flag = 0; 76         for(auto d:test) 77         { 78             if(!d) 79             { 80                 flag = 1;     81             } 82         } 83         if(flag) 84         { 85             cout << "-1" << endl; 86             continue; 87         } 88          89         int m[n] {0}; 90         int result = 0; 91         for(int i = 0;i < n;i ++) 92         { 93             if(m[i]==0) 94             { 95                 for(int j = v.size()-1;j >= 0;j --) 96                 { 97                     if(v[j].first<=i) 98                     { 99                         result ++;100                         for(int k = v[j].first;k <= v[j].second;k ++)101                             m[k] = 1;102                         break;103                     }104                 }105             }106         }107         cout << result << endl;108     }109     return 0;110 }

 

Codeforces-1066B heaters.