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 }
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 }
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 }
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\n", ans); 36 return 0; 37 }