题解：

第一题

#include
      
       using namespace std;#define ll long longconst int M = 1e5 + 10;ll a[M], b[M], ans;priority_queue 
       
         , greater
        
          > Q;int main(){    freopen("buy.in","r",stdin);    freopen("buy.out","w",stdout);    int n;    scanf("%d", &n);    for(int i = 1; i <= n; i++)scanf("%I64d", &a[i]);    for(int i = 1; i <= n; i++)scanf("%I64d", &b[i]);    for(int i = 1; i <= n; i++){        Q.push(a[i]);        if(!Q.empty()){            int u = Q.top();            if(u < b[i]) {                ans += b[i] - u;                Q.pop();                Q.push(b[i]);                }        }    }    printf("%I64d\n",ans);}
        
       
      

 

第二题：

 

#include
      
       using namespace std;#define ll long long;const int M = 1e5 + 10;int n, a[M], sum[M];struct Node{    int mx, tag;    Node *ls, * rs;    void up(){        mx = max(ls->mx, rs->mx);    }    void down(){        if(tag){            ls->tag += tag; rs->tag += tag;            ls->mx += tag; rs->mx += tag;        }        tag = 0;    }}pool[M << 2], *tail = pool, *root;Node * build(int lf = 1, int rg = n){    Node * nd = ++tail;    if(lf == rg);    else {        int mid = (lf + rg) >> 1;        nd->ls = build(lf, mid);        nd->rs = build(mid + 1, rg);    }    return nd;}#define Ls nd->ls, lf, mid#define Rs nd->rs, mid+1, rgvoid insert(int pos, int val, Node * nd = root, int lf = 1, int rg = n){    if(lf == rg)nd->mx = val;    else {        int mid = (lf + rg) >> 1;        if(pos <= mid)insert(pos, val, Ls);        else insert(pos, val, Rs);        nd->up();    }}void modify(int L, int R, int val, Node * nd = root, int lf = 1, int rg = n){    if(L <= lf && rg <= R){        nd->mx += val;        nd->tag += val;    }    else {        nd->down();        int mid = (lf + rg) >> 1;        if(L <= mid)modify(L, R, val, Ls);        if(R > mid) modify(L, R, val, Rs);        nd->up();    }}int query(int L, int R, Node * nd = root, int lf = 1, int rg = n){    if(L <= lf && rg <= R)return nd->mx;    else {        nd->down();        int mid = (lf + rg) >> 1;        int ans = -2e9;        if(L <= mid)ans = query(L, R, Ls);        if(R > mid) ans = max(ans, query(L, R, Rs));        return ans;    }    }int main(){    freopen("invest.in","r",stdin);    freopen("invest.out","w",stdout);    int s, e;    int ans = -2e9;    scanf("%d%d%d", &n, &s, &e);    root = build();    for(int i = 1; i <= e; i++){        scanf("%d", a + i);        sum[i] = sum[i - 1] + a[i];        insert(i, sum[i]);    }    int llf = 1, lf = s, rg = e, now = 1;    ans = max(ans, query(lf, rg));    //cout<
       
        <
       
      

#include
      
       int a[100002],k[100002];int max(int x,int y){    return x>y?x:y; }int qin(){    char ch;    int in=0;    bool flag=0;    while(ch!='-'&&!(ch>='0'&&ch<='9'))       ch=getchar();    if(ch=='-')    {      flag=1;      ch=getchar();    }    do    {      in=in*10+ch-'0';      ch=getchar();    }    while(ch>='0'&&ch<='9');    if(flag)      in*=-1;    return in;}int co(){    freopen("invest.in","r",stdin);    freopen("invest.out","w",stdout);    int n,i,t,head,tail,s,ans=-10000000,j;    scanf("%d%d%d",&n,&s,&t);    for(i=1;i<=n;i++)      a[i]=a[i-1]+qin();    head=tail=1;    for(i=s;i<=n;i++)    {        while(head
       
        t) head++;        while(head
        
       
      

 

 

 第三题：

#include
      
       using namespace std;const int M = 1e6 + 10;#define ll long longconst ll mod = 19930726;char c[M], s[ M << 1 ];ll cnt[M]; int len, pal[M << 1];ll ksm(ll a, ll b){    ll ret = 1;    for( ; b; b >>= 1, a = a * a % mod){        if(b & 1) ret = ret * a % mod;    }    return ret;}void init(){    len = strlen(c);    s[0] = '$';    for(int i = 0; i < len; i++){        s[i * 2 + 1] = '#';        s[i * 2 + 2] = c[i];    }    s[len * 2 + 1] ='#';    s[len * 2 + 2] ='@';    int L = len * 2 + 1;            int id = 1, Maxid = 0;    for(int i = 1; i <= L; i++){        if(Maxid >= i)pal[i] = min(Maxid - i + 1, pal[2 * id - i]);        else pal[i] = 1;        while(s[i - pal[i]] == s[i + pal[i]])pal[i]++;        if(i + pal[i] - 1 > Maxid) id = i, Maxid = i + pal[i] - 1;        if((i&1) == 0)cnt[(pal[i] * 2 - 1) / 2]++;    }    }int main(){    freopen("rehearse.in","r",stdin);    freopen("rehearse.out","w",stdout);    int n; ll k, ans = 1, sum = 0;    cin>>n>>k;    scanf("%s", c);    init();    int limit = n & 1 ? n : n - 1;    for(int i = limit; i > 0; i -= 2){                if(i != 1)cnt[i - 2] += cnt[i];        if(sum + cnt[i] <= k)ans = (ans * ksm(i, cnt[i])) % mod;        else ans = (ans * ksm(i, k - sum)) % mod;        sum += cnt[i];        if(sum >= k)break;    }     if(sum >= k)cout<
       
        <
       
      

今天复制freopen， 两个stdin, 惨痛教训