指路：https://ac.nowcoder.com/acm/contest/900#question

A：风雨无阻（签到题）

https://ac.nowcoder.com/acm/contest/view-submission?submissionId=40697398

#include<bits/stdc++.h>
using namespace std;
const int MAXN=6e5+5;
#define ll long long
ll n;
char s[MAXN];
int main(){
    scanf("%lld",&n);
    scanf("%s",s);
    int len=strlen(s),tmp=0;
    char op=0;
    for(int i=0;i<len;i++){
        if(s[i]<'0'||s[i]>'9') op=s[i],tmp=0;
        else tmp=tmp*10+s[i]-'0';
        if(s[i+1]<'0'||s[i+1]>'9'){
            if(op=='+') n+=tmp;
            else if(op=='-') n-=tmp;
            else if(op=='*') n*=tmp;
            else if(op=='%') n%=tmp;
            else n*=n;
        }
    }
    cout<<abs(n)<<"\n";
    return 0;
}

B：Taeyeon的困惑

思路参考：https://blog.csdn.net/xuxiayang/article/details/90523848以及
https://www.cnblogs.com/y2823774827y/p/10921242.html

#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
multiset<int> s, r;
int a[N];
int main() {
    int n, m, k; scanf("%d%d%d", &n, &m, &k);
    long long sum = 0, ans = 0;
    for(int i = 1; i <= n; i++) {
        int x; scanf("%d", &x);
        a[i] = x;
        sum += x;
        s.insert(x);
        if(s.size() > k) {
            int t = *s.rbegin();
            sum -= t;
            r.insert(t);
            s.erase(s.find(t));
        }
        if(i > m) {
            auto it = r.lower_bound(a[i - m]);
            if(it != r.end() && *it == a[i - m]) r.erase(it);
            else {
                it = s.lower_bound(a[i - m]);
                sum -= a[i - m];
                s.erase(it);
                s.insert(*r.begin());
                sum += *r.begin();
                r.erase(r.begin());
            }
        }
        if(i >= m) ans += sum;
 
    }
    printf("%lld\n", ans);
    return 0;
}

其他不看了，太菜了