【LGR-149-Div.3】洛谷基础赛 #2 & qw Round -1 赛后总结

整体评价

说是普及组难度但感觉比普及组简单一些，因为我普及组从来没有上过300

T1 100 pts

签到题，没什么好说的

#include <iostream>
#include <cstdio>
using namespace std;

int main() {
    int a, b, c, d, e;
    cin >> a >> b >> c >> d >> e;
    int sum = a + b + c + d + e;
    if(sum <= 99) cout << "Gray" << endl;
    else if (sum <= 119) cout << "Blue" << endl;
    else if (sum <= 169) cout << "Green" << endl;
    else if (sum <= 229) cout << "Orange" << endl;
    else cout << "Red" << endl;
    return 0;
}

T2 100pts

找最左边最后边的就可以了

#include <iostream>
using namespace std;
const int maxn = 1e5 + 5;
int a[maxn];
int main() {
    int n;
    cin >> n;
    int ans = 0;
    int left, right;
    left = right = 0;
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    for(int i = 1; i <= n; i++) {
        if(a[i] == 1) {
            left = i;
            break;
        }
    }
    for(int i = n; i >= 0 ;i --) {
        if(a[i] == 1) {
            right = i;
            break;
        }
    }
    if(left != 0 && right != 0)cout << right - left + 1 << endl;
    else cout << 0 << endl;
    return 0;
}

T3 100pts

T3两个小时的时候才做出来，第一次做的时候情况没有考虑完整只得了40分，但是后面提交的时候因为STL的选择不对导致TLE，最后把STL由STL换成了queue才通过了这道题。

这道题就是模拟题吧。

#include <iostream>
#include <queue>
#include <map>
#include <set>        //用了好多STL尝试，最终还是决定用queue
#include <vector>  //本来说STL过不了我就手打，最终还是过了
#include <algorithm>
#include <unordered_set>
using namespace std;
int n;
queue <string> que;
queue <string> playing;
map <string, string> mp;
map <string, int> number;
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    while(n--) {
        string op;
        cin >> op;
        if(op == "start") {
            while(!playing.empty()) {
                que.push(playing.front());
                mp[playing.front()] = "-Watting";
                playing.pop();
            }
            if(que.empty()){
                cout << "Error" << endl;
                continue;
            }
            for(int i = 1, success = 0; success < 2 && !que.empty(); i++) {
                if(number[que.front()] > 1 || mp[que.front()] == "") {
                    number[que.front()]--;
                    que.pop();
                    continue;    
                }
                mp[que.front()] = "-Playing";
                success++;
                playing.push(que.front());
                cout << que.front() << " ";
                que.pop();
            }
            cout << endl;
        }
        else if(op == "arrive") {
            string ar;
            cin >> ar;
            if(mp[ar] == "-Watting" || mp[ar] == "-Playing") {
                cout << "Error" << endl;
                continue;
            }
            mp[ar] = "-Watting";
            number[ar]++;
            que.push(ar);
            cout << "OK" << endl;
        }
        else if(op == "leave") {
            string le;
            cin >> le;
            if(mp[le] == "-Playing" || mp[le] == "") {
                cout << "Error" << endl;
                continue;
            }
            mp[le] = "";
            cout << "OK" << endl;
        }
    }
    return 0;

}

T4 50pts

这道题两种特殊情况一共20pts, 加上了30分的暴力，按理来说暴力应该是能拿60pts，但是我的暴力写挂了，只拿了50

~~话说两个小时我这个蒟蒻都写不出来，我就是个废柴~~

正解应该是二分，但是我实在是没有看出来，看来二分还是不是很熟悉
“`cpp
// U318099 pay
// https://www.luogu.com.cn/problem/U318099?contestId=123900

include

include

include

include <limits.h>

using namespace std;
const int maxn = 1e6 + 10;

define int long long

int n, m;
int a[maxn];
int b[maxn];
long long f[maxn];
int Max = -1;
bool check() {
for(int i = 1; i <= n; i++) {
if(f[i] < a[i]) return false;
}
return true;
}
namespace LS {
void Main() {
for(int i = Max / m/就是因为这里除以了一个m我才卡到50分/; i <= INT_MAX; i++) {
for(int j = 1;j <= m; j++) {
for(int q = max((long long)1, b[j] – i + 1); q <= min(n, b[j] + i – 1); q++) {
f[q] += max(i – abs(b[j] – q), (long long)0);
}
}
if(check()) {
cout << i << endl;
return;
}
for(int i = 1; i <= n; i++) f[i] = 0;
}
}
}
namespace N1 {
void Main() {
cout << a[1] << endl;
}
}
namespace M1 {
void Main() {
int ans = 0;
for(int i = 1; i <= n; i++) {
a[i] += abs(i – b[1]);
ans = max(ans, a[i]);
}
cout << ans << endl;
}
}
signed main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
cin >> m;
for(int i = 1; i <= n; i++) {
cin >> a[i];
Max = max(Max, a[i]);
}
for(int i = 1; i <= m; i++) {
cin >> b[i];
}
if(n == 1) {
N1::Main();
return 0;
}

if(m == 1) {
    M1::Main();
    return 0;
}

LS::Main();

return 0;

}
“