AtCoder Beginner Contest 367 题解:
\(Problem \hspace{2mm} A - Shout \hspace{2mm} Everyday\)
opinion:
~~ code:
#include <bits/stdc++.h>
#define ll long long
#define pii pair <int, int>
using namespace std;
ll a, b, c;
int main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
cin >> a >> b >> c;
if (b <= c) {
if (a < b || a > c) {
cout << "Yes";
} else {
cout << "No";
}
} else {
if (!(a + 24 >= b && a <= c)) {
cout << "Yes";
} else {
cout << "No";
}
}
return 0;
}
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\(Problem \hspace{2mm} B - Cut .0\)
opinion:
code:
#include <bits/stdc++.h>
#define ll long long
#define pii pair <int, int>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
string s; cin >> s;
bool fg = false;
int n = s.size();
while (s[n - 1] == '0') n --;
if (s[n - 1] == '.') n -= 1;
for (int i = 0; i < n; ++i)
cout << s[i];
return 0;
}
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\(Problem \hspace{2mm} C - Enumerate \hspace{2mm} Sequences\)
opinion:
code:
#include <bits/stdc++.h>
#define ll long long
#define pii pair <int, int>
using namespace std;
const int N = 1e6 + 10;
int n, k, a[N], x[N];
inline void dfs(int step, int ret) {
if (step > n) {
if (ret % k == 0) {
for (int i = 1; i <= n; ++i)
cout << x[i] << " ";
cout << "\n";
}
return ;
}
for (int i = 1; i <= a[step]; ++i) {
x[step] = i;
dfs(step + 1, ret + i);
x[step] = 0;
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
cin >> n >> k;
for (int i = 1; i <= n; ++i)
cin >> a[i];
dfs(1, 0);
return 0;
}
~~
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\(Problem \hspace{2mm} D - Pedometer\)
opinion:
code:
#include <bits/stdc++.h>
#define ll long long
#define pii pair <int, int>
using namespace std;
const int N = 1e6 + 10;
ll n, m, a[N], cnt[N], pre[N];
signed main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> a[i];
a[n + i] = a[i];
}
for (int i = 2; i <= n + n - 1; i++) {
pre[i] = pre[i - 1] + a[i - 1];
pre[i] %= m;
}
for (int i = 1; i <= n; i++)
cnt[pre[i]]++;
ll ans = 0;
for (int i = 1; i <= n; i++) {
ans += cnt[pre[i]] - 1;
cnt[pre[i + n]]++;
cnt[pre[i]]--;
}
cout << ans;
return 0;
}
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\(Problem \hspace{2mm} F - Rearrange \hspace{2mm} Query\)
opinion:
Hash + 前缀和,竟然没被卡掉,绷不住了。
code:
#include <bits/stdc++.h>
#include <random>
#define ll long long
#define pii pair <int, int>
using namespace std;
const int N = 1e6 + 10;
const ll mod = 1e9 + 7;
ll n, q, a[N], b[N];
ll Hash[N];
ll pre_a[N], pre_b[N];
signed main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
cin >> n >> q;
for (int i = 1; i <= n; ++i)
cin >> a[i];
for (int i = 1; i <= n; ++i)
cin >> b[i];
srand(time(NULL));
for (int i = 1; i <= n; ++i)
Hash[i] = rand() % mod;
for (int i = 1; i <= n; ++i) {
(pre_a[i] = pre_a[i - 1] + Hash[a[i]]) %= mod;
(pre_b[i] = pre_b[i - 1] + Hash[b[i]]) %= mod;
}
while (q -- ) {
int l[2], r[2];
cin >> l[0] >> r[0] >> l[1] >> r[1];
ll ans1 = pre_a[r[0]] - pre_a[l[0] - 1] + mod;
ll ans2 = pre_b[r[1]] - pre_b[l[1] - 1] + mod;
if (ans1 % mod == ans2 % mod) puts("Yes");
else puts("No");
}
return 0;
}
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