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SDU暑假排位第一场 (Gym - 100889)

啊今天有点挂机啊

D题和队友暴力后发现一组数据跑得飞快

然后遇上1e5组数据就没了.....

然后我疯狂优化暴力

然后去世了

最后半小时F也没写出来

主要还是最后有点慌并且没有考虑清楚

导致情况越写越多最后写了23个if

这肯定是完蛋了啊

A:签到

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#include <bits/stdc++.h>

#define int long long
typedef long long ll;
using namespace std;
const int N = 2e5 + 10;
int n,a[N];

void ss() {
    cin >> n;
    for (int i = 1; i <= n; i++)cin >> a[i];
    sort(a + 1,a + 1 + n);
    int ans = 0;
    for (int i = 1; i <= n / 2; i++) ans += a[n - i + 1] - a[i];
    cout << ans << endl;
}

int32_t main() {
    ios::sync_with_stdio(0),cin.tie(0);
    int T;
    cin >> T;
    while (T--)ss();
}
View Code

B:签到

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#include<iostream>
#include<cstdio>
#define MAXN 100005
#define ll long long
using namespace std;
int n;
ll a[MAXN];

int solve(){
    int l = 1,r = n,cnt = 0;
    ll lsum = 0,rsum = 0;
    if (n == 1) return 0;

    while (l <= r) {
        if (lsum < rsum) {
            ++cnt;
            lsum += a[L++];
        }
        else if (lsum > rsum) {
            ++cnt;
            rsum += a[r--];
        }
        else {
            lsum = a[L++];
            rsum = a[r--];
        }
    }
    if (lsum != rsum) ++ cnt;
    return cnt;
}

void input(){
    int T;
    scanf("%d",&T);
    
    while (T--){
        scanf("%d",&n);
        for (int i = 1; i <= n;++i){
            scanf("%d",&a[i]);
        }
        int ans = solve();
        printf("%d\n",ans);
    }
}

int main(){
    input();
    return 0;
}
View Code

C:交互题 贪心的贴墙走 

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#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int x,y;
int dx[] = {1,0,-1,0};
int dy[] = {0,1,-1};

char iin[60];
char* str[] = {"DOWN","RIGHT","UP","LEFT"};

bool judge(int nx,int ny,int dir){
    if (!x || !y) {
        return 0;
    }
    cout << "LOOK " << str[dir] << endl;
    cin >> iin;
    return !strcmp(iin,"SAFE");
}

void input(){
    int dir = 1;
    x = y = 1;
    while (true) {
        dir = (dir+3) % 4;
        while (!judge(x+dx[dir],y+dy[dir],dir)) {
            dir = (dir+1) % 4;
        }
        x += dx[dir];
        y += dy[dir];
        cout << "GO " << str[dir] << endl;
        cin >> iin;
        if (!strcmp(iin,"YES")) {
            break;
        }
    }
}

int main(){
    input();
    return 0;
}
View Code

D:

一开始想的暴力是我暴力分解N 把它分解成一些数的乘积

那么这些数可以作为某个ans的质因数指数

在选取质因子 再去重复

然后t的死死的

在这个思路上挣扎了1小时之后投了 扔给队友

幸好最后一小时队友找到了简单解法

对于一个ans 把他分解为p1^a1*p2^a2*...*pm^am

那么有(a1+1)(a2+1)*...*(am+1)==n

对n分解为p1^b1*p2^b2*...*pk^bk

对于b1个p1 把他分配到m个括号中

设第i个括号分了ci 有 c1+c2+...+cm=b1

简单的组合数问题

同理 p2 pk也是  最后乘起来

这样就很巧妙的避免了重复

因为就算某两个括号的值相同

但是他们是作为两个不同的素数的指数

ans之间一定不同 故不重复

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#include <bits/stdc++.h>

#define int long long
#pragma GCC optimize(3)
#define endl "\n"
typedef long long ll;
using namespace std;
ll mod = 1e9 + 7;

int n,m;

vector<int> tmp;
map<int,map<int,int> > PP;
int f[100000];
int f1[110];
ll ans;

ll qpow(ll a,ll n) {
    ll ans = 1;
    for (; n; n >>= 1,a = a * a % mod) if (n & 1) ans = ans * a % mod;
    return ans;
}

vector<int> c;

void get(int n) {
    for (int i = 2; i * i <= n; i++) {
        if (n % i == 0) {
            int cnt = 0;
            while (n % i == 0)n /= i,cnt++;
            c.push_back(cnt);
        }
    }
    if (n > 1)c.push_back(1);
}

int C(int n,int m) {
    if (m > n)return 0;
    int res = 1;
    for (int i = n; i >= n - m + 1; i--) {
        res = (res * i) % mod;
    }
    return res * f1[m] % mod;
}


void ss() {
    cin >> n >> m;
    c.clear();
    int ans = 1;
    get(n);
    for (auto p:c) {
        ans = (ans * C(m + p - 1,p)) % mod;
    }
    cout << ans << endl;
}

int32_t main() {
    ios::sync_with_stdio(0),cin.tie(0);
    f1[0] = 1;
    for (int i = 1; i <= 100; i++) f1[i] = 1LL * f1[i - 1] * i % mod;
    for (int i = 1; i <= 100; i++) f1[i] = qpow(f1[i],mod - 2);
    int T;
    cin >> T;
    while (T--)ss();
}
View Code

E:签到题

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#include<cstdio>
using namespace std;
int T,n,m;
int main(){
    scanf("%d",&T);
    while(T--){
        int u,v,falg=0;
        scanf("%d%d",&n,&m);
        for(int i=1;i<=m;i++){
            scanf("%d%d",&u,&v);
            if(u==1&&v==n)falg=1;
        }
        if(falg)printf("Jorah Mormont\n");
        else printf("Khal Drogo\n");
    }
    return 0;
}
View Code

F:

一开始的思路是,按A矩阵的长宽离散坐标系并把A平移到原点

然后考虑A平移后和B相交的情况

四个角 四个角附近的8个格子 B过坐标轴的四个各自 四个角向内部走一个的四个格子.....

然后就没了

这题就属于没想好就开始摸键盘 一开始大体想的情况很少 然后写的过程中打补丁

然后就乱了

比较简洁的做法也有很多

 可以先走到角上 然后bfs2步

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#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll T,ax,ay,aw,ah,bx,by,bw,bh,ans,k;
ll xx[4]={0,-1};
ll yy[4]={1,0};
struct node{
    ll x,y,s;
    node(ll xx,ll yy,ll ss){
        x=xx;y=yy;s=ss;
    }
};
queue<node>q;
ll Cal(ll x,ll y){
    ll dx=max(0ll,min(x+aw,bx+bw)-max(x,bx));
    ll dy=max(0ll,min(y+ah,by+bh)-max(y,by));
    return dx*dy;
}
ll ss(ll x,ll y){
    ll res=0,lim=min(2ll,k);
    q.push(node(x,0));
    while(!q.empty()){
        node Now=q.front();q.pop();
        res=max(res,Cal(Now.x,Now.y));
        if(Now.s==lim)continue;
        for(ll i=0;i<4;i++){
            ll nx=Now.x+xx[i]*aw;
            ll ny=Now.y+yy[i]*ah;
            q.push(node(nx,ny,Now.s+1));
        }
    }
    return res;
}
int main(){
    scanf("%lld",&T);
    while(T--){
        scanf("%lld%lld%lld%lld%lld%lld%lld%lld%lld",&ax,&ay,&aw,&ah,&bx,&by,&bw,&bh,&k);
        ll dx,dy;ans=0;
        if(bx>=ax+aw)dx=(bx-ax)/aw;
        else if(bx+bw<=ax)dx=(ax-bx-bw)/aw+1;
        else dx=0;
        if(by>=ay+ah)dy=(by-ay)/ah;
        else if(by+bh<=ay)dy=(ay-by-bh)/ah+1;
        else dy=0;
        k-=dx+dy;
        if(k<0){
            printf("0\n");continue;
        }
        ans=max(ans,ss(ax+dx*aw,ay+dy*ah));
        ans=max(ans,ss(ax-dx*aw,ay-dy*ah));
        ans=max(ans,ay-dy*ah));
        printf("%lld\n",ans);
    }
    return 0;
}
View Code

 

G:数位DP

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#include<bits/stdc++.h> 
#define ll long long
using namespace std;
ll T,L,R,A,B,f[100][2][2][2][2];
ll Dfs(ll Now,ll okx1,ll okx2,ll oky,ll okz){
    if(Now<0)return 0;
    if(f[Now][okx1][okx2][oky][okz]!=-1)return f[Now][okx1][okx2][oky][okz];
    ll xl=0,xr=1,yl=0,yr=1,zl=0,zr=1;
    if(okx1)xl=(L>>Now)&1;
    if(okx2)xr=(R>>Now)&1;
    if(oky)yr=(A>>Now)&1;
    if(okz)zr=(B>>Now)&1;
    ll res=0;
    for(ll i=xl;i<=xr;i++)
        for(ll j=yl;j<=yr;j++)
            for(ll k=zl;k<=zr;k++){
                ll tis=((i^j)+(j&k)+(k^i))*(1ll<<Now);
                res=max(res,tis+Dfs(Now-1,okx1&&i==xl,okx2&&i==xr,oky&&j==yr,okz&&k==zr));
            }
    return f[Now][okx1][okx2][oky][okz]=res;
}
int main(){
    scanf("%lld",&T);
    while(T--){
        memset(f,-1,sizeof(f));
        scanf("%lld%lld%lld%lld",&L,&R,&A,&B);
        printf("%lld\n",Dfs(62,1));
    }
    return 0;
}
View Code

H:二分+几何

平移到原点之后 在能和x正半轴产生交点的边中 交点横坐标和距离原点的距离(凸包上逆时针距离几个点)是有单调性的

二分

最后其实不用平移旋转每个点 只需要把x=k这个线挪动就好了

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#include<bits/stdc++.h> 
#define db double
#define Vector Point
#define maxn 100010
using namespace std;
struct Point{
    db x,y;
    Point(db X=0,db Y=0){x=X;y=Y;}
};
Vector operator + (Vector A,Vector B){return Vector(A.x+B.x,A.y+B.y);}
Vector operator - (Vector A,Vector B){return Vector(A.x-B.x,A.y-B.y);}
Vector operator * (Vector A,db p){return Vector(A.x*p,A.y*p);}
Vector operator / (Vector A,db p){return Vector(A.x/p,A.y/p);}
bool operator < (const Point &a,const Point &b){
    return a.x<b.x||(a.x==b.x&&a.y<b.y);
}
const db eps=1e-10;
int dcmp(db x){
    if(fabs(x)<eps)return 0;
    else return x<0?-1:1;
}
bool operator ==(const Point &a,const Point &b){
    return dcmp(a.x-b.x)==0&&dcmp(a.y-b.y)==0;
}
db Dot(Vector A,Vector B){return A.x*B.x+A.y*B.y;}//A B 点积
db Length(Vector A){return sqrt(Dot(A,A));}//向量长度
db Angle(Vector A,Vector B){return acos(Dot(A,B)/Length(A)/Length(B));}//A B 夹角
db Cross(Vector A,Vector B){return A.x*B.y-A.y*B.x;}//A B 叉积
db Area2(Point A,Point B,Point C){return Cross(B-A,C-A);}//A B 构成的平行四边形面积2倍
Vector Rotate(Vector A,db rad){//A逆时针旋转rad
    return Vector(A.x*cos(rad)-A.y*sin(rad),A.x*sin(rad)+A.y*cos(rad));
}
Vector normal(Vector A){//返回A的单位法向量
    return Vector(-A.y/Length(A),A.x/Length(A));
}
//点和直线
Point GetLineIntersection(Point P,Vector v,Point Q,Vector w){//返回直线P+tv Q+tw的交点
    Vector u=P-Q;
    db t=Cross(w,u)/Cross(v,w);
    return P+v*t;
}
db distancetoLine(Point P,Point A,Point B){//P到直线AB的距离
    Vector v1=B-A,v2=P-A;
    return fabs(Cross(v1,v2)/Length(v1));
}
db distancetoSegment(Point P,Point B){//P到线段AB的距离
    if(A==B)return Length(P-A);
    Vector v1=B-A,v2=P-A,v3=P-B;
    if(dcmp(Dot(v1,v2))<0)return Length(v2);
    else if(dcmp(Dot(v1,v3))>0)return Length(v3);
    else return fabs(Cross(v1,v2))/Length(v1);
}
Point GetLineProjection(Point P,Point B){//P在直线AB上的投影
    Vector v=B-A;
    return A+v*(Dot(v,P-A)/Dot(v,v));
}
//bool isSL(Point p1,Point p2,Point q1,Point q2){//判断直线p1p2和线段q1q2有无交点(不严格)
//     return dcmp(Cross(p2-p1,q1-p1)*Cross(p2-p1,q2-p1))!=1;
//}
//bool isSL_s(Point p1,Point q2){//判断直线p1p2和线段q1q2有无交点(严格)
//     return dcmp(Cross(p2-p1,q2-p1))==-1;
//}
int isll(Point k1,Point k2,Point k3,Point k4){// 求直线 k1,k2 和 k3,k4 的交点
    return dcmp(Cross(k3-k1,k4-k1)-Cross(k3-k2,k4-k2))!=0;
}
Point getLL(Point k1,Point k4){
    db w1=Cross(k1-k3,k4-k3),w2=Cross(k4-k3,k2-k3); return (k1*w2+k2*w1)/(w1+w2);
}
bool intersect(db l1,db r1,db l2,db r2){
    if(dcmp(l1-r1)==1)swap(l1,r1);if(dcmp(l2-r2)==1)swap(l2,r2);
    return !(dcmp(r1-l2)==-1||dcmp(r2-l1)==-1);
}
bool isSS(Point p1,Point q2){
    return intersect(p1.x,p2.x,q1.x,q2.x)&&intersect(p1.y,p2.y,q1.y,q2.y)&&
    dcmp(Cross(p2-p1,q2-p1))!=1&&
    dcmp(Cross(q2-q1,p1-q1)*Cross(q2-q1,p2-q1))!=1;
}
bool isSS_s(Point p1,Point q2){
    return dcmp(Cross(p2-p1,q2-p1))==-1
    &&dcmp(Cross(q2-q1,p2-q1))==-1;
}
db Area(vector<Point> A){ // 多边形用 vector<point> 表示,逆时针  求面积 
    db ans=0;
    for (int i=0;i<A.size();i++) ans+=Cross(A[i],A[(i+1)%A.size()]);
    return ans/2;
}
int n,Q;
Point p[maxn];
bool Judge(int pl,int pr,int dis,int k){
    int a=(pr+dis)%n;
    int b=(a+1)%n;
    Point ins=getLL(p[a],p[b],p[pl],p[pr]);
    return dcmp(Length(ins-p[pl])-Length(ins-p[pr]))>0&&dcmp(Length(ins-p[pl])-k)<=0;
}
bool Check(int pl,int b,int k){
    int a=(b-1+n)%n;
    Point ins=getLL(p[a],p[pr]);
    return dcmp(Length(ins-p[pl])-k)==0;
}
int main(){
    scanf("%d%d",&Q);
    for(int i=0;i<n;i++){
        scanf("%lf%lf",&p[i].x,&p[i].y);
    }
    int pl,pr,k,ans=-1;
    while(Q--){
        scanf("%d%d",&pl,&k);pr=(pl+1)%n;
        int l=0,r=n-1;
        while(l<=r){
            int mid=(l+r)/2;
            if(Judge(pl,mid,k)){
                ans=(pr+mid+1)%n;l=mid+1;
            }
            else r=mid-1;
        }
        if(Check(pl,k))printf("%d %d\n",(ans-1+n)%n,ans);
        else printf("%d\n",ans);
    }
    return 0;
} 
/*
7 3
5 5
2 6
0 5
-1 3
0 0
6 0
6 3
4 7
4 8
4 10000



7 3
5 4
2 5
0 4
-1 2
0 0
6 0
6 2
4 7
4 8
4 10000
*/
View Code

L:矩阵优化最短路dp

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#include <bits/stdc++.h>

#define int long long
typedef long long ll;
using namespace std;

const int MT = 200;

int n,m,k;

ll mod = 1e9 + 7;
ll inf = 3e18;

struct Matrix {
    pair<int,int> v[MT][MT];

    void init() {
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
                v[i][j] = {inf,0};
    }

    Matrix operator*(const Matrix B) const {
        Matrix C;
        C.init();
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                for (int k = 1; k <= n; k++) {
                    if (v[i][k].first + B.v[k][j].first < C.v[i][j].first) {
                        C.v[i][j].first = v[i][k].first + B.v[k][j].first;
                    }
                }
                for (int k = 1; k <= n; k++) {
                    if (v[i][k].first + B.v[k][j].first == C.v[i][j].first) {
                        (C.v[i][j].second += v[i][k].second * B.v[k][j].second) %= mod;
                    }
                }
            }
        }
        return C;
    }
} mp;


int32_t main() {
    ios::sync_with_stdio(0),cin.tie(0);
    cin >> n >> m >> k;
    mp.init();
    while (m--) {
        int u,w;
        cin >> u >> v >> w;
        mp.v[u][v] = {w,1};
        mp.v[v][u] = {w,1};
    }
    Matrix ans = mp;
    k--;
    for (; k; k >>= 1,mp = mp * mp) if (k & 1) ans = ans * mp;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            if (ans.v[i][j].first >= inf)cout << "X 0 ";
            else
                cout << ans.v[i][j].first << " " << ans.v[i][j].second << " ";
        }
        cout << endl;
    }
}
View Code

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