Submission #25425

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
25425	2017-06-22T06:37:27 Z	tlwpdus	Watching (JOI13_watching)	C++14	Compilation error	0 ms	0 KB

watching

#include <bits/stdc++.h>

using namespace std;

int dyn[2100][2100];
int prev[2][2100];
int n, p, q;
int arr[2100];

bool ok(int w) {
    int i, j;
    for (i=1;i<=n;i++) {
        prev[0][i] = upper_bound(arr,arr+i,arr[i]-w)-arr-1;
        prev[1][i] = upper_bound(arr,arr+i,arr[i]-w*2)-arr-1;
    }
    for (i=1;i<=n;i++) {
        for (j=0;j<=n;j++) {
            dyn[i][j] = min(((j)?dyn[prev[1][i]][j-1]:987654321),dyn[prev[0][i]][j]+1);
        }
    }
    return dyn[n][min(q,n)]<=p;
}

int main() {
    int i;
    scanf("%d%d%d",&n,&p,&q);
    arr[0] = -(1e9+10);
    for (i=1;i<=n;i++) scanf("%d",&arr[i]);
    sort(arr,arr+n+1);
    int s = 1, e = 5e8+3;
    while(s<=e) {
        int m = (s+e)>>1;
        if (ok(m)) e = m-1;
        else s = m+1;
    }
    printf("%d\n",s);
    return 0;
}

Compilation message

watching.cpp: In function 'bool ok(int)':
watching.cpp:13:9: error: reference to 'prev' is ambiguous
         prev[0][i] = upper_bound(arr,arr+i,arr[i]-w)-arr-1;
         ^
watching.cpp:6:5: note: candidates are: int prev [2][2100]
 int prev[2][2100];
     ^
In file included from /usr/include/c++/5/bits/stl_algobase.h:66:0,
                 from /usr/include/c++/5/bits/char_traits.h:39,
                 from /usr/include/c++/5/ios:40,
                 from /usr/include/c++/5/istream:38,
                 from /usr/include/c++/5/sstream:38,
                 from /usr/include/c++/5/complex:45,
                 from /usr/include/c++/5/ccomplex:38,
                 from /usr/include/x86_64-linux-gnu/c++/5/bits/stdc++.h:52,
                 from watching.cpp:1:
/usr/include/c++/5/bits/stl_iterator_base_funcs.h:193:5: note:                 template<class _BidirectionalIterator> _BidirectionalIterator std::prev(_BidirectionalIterator, typename std::iterator_traits<_Iter>::difference_type)
     prev(_BidirectionalIterator __x, typename
     ^
watching.cpp:14:9: error: reference to 'prev' is ambiguous
         prev[1][i] = upper_bound(arr,arr+i,arr[i]-w*2)-arr-1;
         ^
watching.cpp:6:5: note: candidates are: int prev [2][2100]
 int prev[2][2100];
     ^
In file included from /usr/include/c++/5/bits/stl_algobase.h:66:0,
                 from /usr/include/c++/5/bits/char_traits.h:39,
                 from /usr/include/c++/5/ios:40,
                 from /usr/include/c++/5/istream:38,
                 from /usr/include/c++/5/sstream:38,
                 from /usr/include/c++/5/complex:45,
                 from /usr/include/c++/5/ccomplex:38,
                 from /usr/include/x86_64-linux-gnu/c++/5/bits/stdc++.h:52,
                 from watching.cpp:1:
/usr/include/c++/5/bits/stl_iterator_base_funcs.h:193:5: note:                 template<class _BidirectionalIterator> _BidirectionalIterator std::prev(_BidirectionalIterator, typename std::iterator_traits<_Iter>::difference_type)
     prev(_BidirectionalIterator __x, typename
     ^
watching.cpp:18:38: error: reference to 'prev' is ambiguous
             dyn[i][j] = min(((j)?dyn[prev[1][i]][j-1]:987654321),dyn[prev[0][i]][j]+1);
                                      ^
watching.cpp:6:5: note: candidates are: int prev [2][2100]
 int prev[2][2100];
     ^
In file included from /usr/include/c++/5/bits/stl_algobase.h:66:0,
                 from /usr/include/c++/5/bits/char_traits.h:39,
                 from /usr/include/c++/5/ios:40,
                 from /usr/include/c++/5/istream:38,
                 from /usr/include/c++/5/sstream:38,
                 from /usr/include/c++/5/complex:45,
                 from /usr/include/c++/5/ccomplex:38,
                 from /usr/include/x86_64-linux-gnu/c++/5/bits/stdc++.h:52,
                 from watching.cpp:1:
/usr/include/c++/5/bits/stl_iterator_base_funcs.h:193:5: note:                 template<class _BidirectionalIterator> _BidirectionalIterator std::prev(_BidirectionalIterator, typename std::iterator_traits<_Iter>::difference_type)
     prev(_BidirectionalIterator __x, typename
     ^
watching.cpp:18:70: error: reference to 'prev' is ambiguous
             dyn[i][j] = min(((j)?dyn[prev[1][i]][j-1]:987654321),dyn[prev[0][i]][j]+1);
                                                                      ^
watching.cpp:6:5: note: candidates are: int prev [2][2100]
 int prev[2][2100];
     ^
In file included from /usr/include/c++/5/bits/stl_algobase.h:66:0,
                 from /usr/include/c++/5/bits/char_traits.h:39,
                 from /usr/include/c++/5/ios:40,
                 from /usr/include/c++/5/istream:38,
                 from /usr/include/c++/5/sstream:38,
                 from /usr/include/c++/5/complex:45,
                 from /usr/include/c++/5/ccomplex:38,
                 from /usr/include/x86_64-linux-gnu/c++/5/bits/stdc++.h:52,
                 from watching.cpp:1:
/usr/include/c++/5/bits/stl_iterator_base_funcs.h:193:5: note:                 template<class _BidirectionalIterator> _BidirectionalIterator std::prev(_BidirectionalIterator, typename std::iterator_traits<_Iter>::difference_type)
     prev(_BidirectionalIterator __x, typename
     ^
watching.cpp: In function 'int main()':
watching.cpp:26:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d",&n,&p,&q);
                             ^
watching.cpp:28:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (i=1;i<=n;i++) scanf("%d",&arr[i]);
                                           ^