Codeforces Round #617 (Div. 3)

这场练练golang

题目链接：https://codeforces.com/contest/1296

A：

白给

 1 package main
 2 
 3 import "fmt"
 4 
 5 const (
 6     maxn = 2010
 7 )
 8 
 9 var (
10     a    [maxn]int
11     n, t int
12 )
13 
14 func main() {
15     fmt.Scan(&t)
16     for cnt := 1; cnt <= t; cnt++ {
17         var odd, even int
18         fmt.Scan(&n)
19         for i := 1; i <= n; i++ {
20             var x int
21             fmt.Scan(&x)
22             if x&1 != 0 {
23                 odd++
24             } else {
25                 even++
26             }
27         }
28         if odd == 0 {
29             fmt.Println("NO")
30         } else if even == 0 {
31             if n&1 != 0 {
32                 fmt.Println("YES")
33             } else {
34                 fmt.Println("NO")
35             }
36         } else {
37             fmt.Println("YES")
38         }
39     }
40 }

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B：

注意每次给钱时保留个位不要给就行

 1 package main
 2 
 3 import "fmt"
 4 
 5 var (
 6     t int
 7 )
 8 
 9 func main() {
10     fmt.Scan(&t)
11     for cnt := 1; cnt <= t; cnt++ {
12         var s, ans, tmp int
13         fmt.Scan(&s)
14         tmp = s
15         for {
16             var refound, yu = tmp / 10, tmp % 10
17             ans += refound * 10
18             if tmp < 10 {
19                 ans += tmp
20                 break
21             }
22             tmp = refound + yu
23         }
24         fmt.Println(ans)
25     }
26 }

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C：

做偏移量(x,y)到字符串下标的映射即可

 1 package main
 2 
 3 import "fmt"
 4 
 5 const maxn int = 2e5 + 10
 6 
 7 type pair struct {
 8     fir, sec int
 9 }
10 
11 var t int
12 
13 func main() {
14     fmt.Scan(&t)
15     for ; t > 0; t-- {
16         var n int
17         var s string
18         fmt.Scan(&n, &s)
19         s = " " + s
20         var ans, l, r, x, y = n + 1, 0, 0, 0, 0
21         m := make(map[pair]int)
22         m[pair{0, 0}] = 1
23         for i := 1; i < len(s); i++ {
24             switch s[i] {
25             case 'L':
26                 x--
27             case 'R':
28                 x++
29             case 'U':
30                 y++
31             case 'D':
32                 y--
33             }
34             v := m[pair{x, y}]
35             if v != 0 {
36                 if ans > (i - v + 1) {
37                     ans = i - v + 1
38                     l = v
39                     r = i
40                 }
41             }
42             m[pair{x, y}] = i + 1
43         }
44         if ans == (n + 1) {
45             fmt.Println("-1")
46         } else {
47             fmt.Println(l, r)
48         }
49     }
50 }

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D：

对每个数，模a+b之后计算余数要a攻击次数，再O(n)贪心即可

 1 /* basic header */
 2 #include <bits/stdc++.h>
 3 /* define */
 4 #define ll long long
 5 #define dou double
 6 #define pb emplace_back
 7 #define mp make_pair
 8 #define sot(a,b) sort(a+1,a+1+b)
 9 #define rep1(i,a,b) for(int i=a;i<=b;++i)
10 #define rep0(i,a,b) for(int i=a;i<b;++i)
11 #define eps 1e-8
12 #define int_inf 0x3f3f3f3f
13 #define ll_inf 0x7f7f7f7f7f7f7f7f
14 #define lson (curpos<<1)
15 #define rson (curpos<<1|1)
16 /* namespace */
17 using namespace std;
18 /* header end */
19 
20 const int maxn = 2e5 + 10;
21 int n, a, b, k, ans, h[maxn];
22 
23 int main() {
24     scanf("%d%d%d%d", &n, &a, &b, &k);
25     for (int i = 0; i < n; i++) {
26         scanf("%d", &h[i]);
27         h[i] %= a + b;
28         if (!h[i]) h[i] = a + b;
29         h[i] = (h[i] - 1) / a;
30     }
31     sort(h, h + n);
32     for (int i = 0; i < n && k >= h[i]; i++) {
33         k -= h[i]; ans++;
34     }
35     printf("%d
", ans);
36     return 0;
37 }

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