Codeforces Round #583 (Div.1+Div.2)

不太友好的一场。

题目链接：https://codeforces.com/contest/1214

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A：

想了很久优美做法，发现还不如直接一发暴力正确。

/* basic header */
#include <bits/stdc++.h>
/* define */
#define ll long long
#define dou double
#define pb emplace_back
#define mp make_pair
#define sot(a,b) sort(a+1,a+1+b)
#define rep1(i,a,b) for(int i=a;i<=b;++i)
#define rep0(i,a,b) for(int i=a;i<b;++i)
#define eps 1e-8
#define int_inf 0x3f3f3f3f
#define ll_inf 0x7f7f7f7f7f7f7f7f
#define lson (curpos<<1)
#define rson (curpos<<1|1)
/* namespace */
using namespace std;
/* header end */

int n, d, e;

int main() {
    scanf("%d%d%d", &n, &d, &e);
    int dollarUnit = d, euroUnit = e * 5, ans = n;
    for (int numOfDollar = 0; numOfDollar <= n / dollarUnit; numOfDollar++) {
        int remainRubles = n - numOfDollar * dollarUnit;
        remainRubles -= remainRubles / euroUnit * euroUnit;
        ans = min(ans, remainRubles);
    }
    for (int numOfEuro = 0; numOfEuro <= n / euroUnit; numOfEuro += 5) {
        int remainRubles = n - numOfEuro * euroUnit;
        remainRubles -= remainRubles / dollarUnit * dollarUnit;
        ans = min(ans, remainRubles);
    }
    printf("%d
", ans);
    return 0;
}

B：

比A简单多了的傻题。

/* basic header */
#include <bits/stdc++.h>
/* define */
#define ll long long
#define dou double
#define pb emplace_back
#define mp make_pair
#define sot(a,b) sort(a+1,a+1+b)
#define rep1(i,a,b) for(int i=a;i<=b;++i)
#define rep0(i,a,b) for(int i=a;i<b;++i)
#define eps 1e-8
#define int_inf 0x3f3f3f3f
#define ll_inf 0x7f7f7f7f7f7f7f7f
#define lson (curpos<<1)
#define rson (curpos<<1|1)
/* namespace */
using namespace std;
/* header end */

int b, g, n;

int main() {
    scanf("%d%d%d", &b, &g, &n);
    ll ans = 0;
    for (int i = 0; i <= b; i++)
        if (n - i >= 0 && n - i <= g) ans++;
    printf("%lld
", ans);
    return 0;
}

C：

check一次看看是否合法即可。

/* basic header */
#include <bits/stdc++.h>
/* define */
#define ll long long
#define dou double
#define pb emplace_back
#define mp make_pair
#define sot(a,b) sort(a+1,a+1+b)
#define rep1(i,a,b) for(int i=a;i<=b;++i)
#define rep0(i,a,b) for(int i=a;i<b;++i)
#define eps 1e-8
#define int_inf 0x3f3f3f3f
#define ll_inf 0x7f7f7f7f7f7f7f7f
#define lson (curpos<<1)
#define rson (curpos<<1|1)
/* namespace */
using namespace std;
/* header end */

const int maxn = 2e5 + 10;
int n;
char s[maxn];

int main() {
    scanf("%d", &n);
    scanf("%s", s + 1);
    if (n & 1) return puts("No"), 0;
    stack<int>st;
    while (!st.empty()) st.pop();
    for (int i = 1; i <= n; i++) {
        if (s[i] == '(') st.push(0);
        if (s[i] == ')') {
            if (!st.empty() && st.top() == 0) st.pop();
            else st.push(1);
        }
    }
    if (st.empty()) return puts("Yes"), 0;
    else {
        if ((int)st.size() != 2) return puts("No"), 0;
        int tmp1 = st.top(), tmp2;
        st.pop();
        tmp2 = st.top();
        if (tmp1 != tmp2) return puts("Yes"), 0;
        else return puts("No"), 0;
    }
    return 0;
}

D：

大模拟。(跑了

E：

SB构造题。

/* basic header */
#include <bits/stdc++.h>
/* define */
#define ll long long
#define dou double
#define pb emplace_back
#define mp make_pair
#define sot(a,b) sort(a+1,a+1+b)
#define rep1(i,a,b) for(int i=a;i<=b;++i)
#define rep0(i,a,b) for(int i=a;i<b;++i)
#define eps 1e-8
#define int_inf 0x3f3f3f3f
#define ll_inf 0x7f7f7f7f7f7f7f7f
#define lson (curpos<<1)
#define rson (curpos<<1|1)
/* namespace */
using namespace std;
/* header end */

const int maxn = 2e5 + 10;

pair<int, int>a[maxn];
vector<int>s;
int n;

int main() {
    scanf("%d", &n);
    for (int i = 1; i <= n; i++)
        scanf("%d", &a[i].first), a[i].second = 2 * i - 1;
    sort(a + 1, a + n + 1);
    reverse(a + 1, a + n + 1);
    s.resize(1);
    for (int i = 1; i <= n; i++) s.push_back(a[i].second);
    for (int i = 1; i <= n - 1; i++) printf("%d %d
", a[i].second, a[i + 1].second);
    for (int i = 1; i <= n; i++) {
        int j = i + a[i].first - 1;
        printf("%d %d
", a[i].second + 1, s[j]);
        if (j == (int)s.size() - 1) s.push_back(a[i].second + 1);
    }
    return 0;
}