Saruman the White must lead his army along a straight path from Isengard to Helm’s Deep. To keep track
of his forces, Saruman distributes seeing stones, known as palantirs, among the troops. Each palantir has a
maximum effective range of R units, and must be carried by some troop in the army (i.e., palantirs are not
allowed to “free float” in mid-air). Help Saruman take control of Middle Earth by determining the minimum
number of palantirs needed for Saruman to ensure that each of his minions is within R units of some palantir.
The input test file will contain multiple cases. Each test case begins with a single line containing an integer
R, the maximum effective range of all palantirs (where 0 ≤ R ≤ 1000), and an integer n, the number of
troops in Saruman’s army (where 1 ≤ n ≤ 1000). The next line contains n integers, indicating the positions
x1, . . . , xn of each troop (where 0 ≤ xi ≤ 1000). The end-of-file is marked by a test case with R = n = −1.
For each test case, print a single integer indicating the minimum number of palantirs needed.
0 3 10 20 20 10 7 70 30 1 7 15 20 50 -1 -1
2 4
Migrated from old NTUJ.
| No. | Testdata Range | Score |
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