[BZOJ 1033][ZJOI2008]杀蚂蚁antbuster

1033: [ZJOI2008]杀蚂蚁antbuster

Time Limit: 10 Sec Memory Limit: 128 MB
Submit: 1200 Solved: 507
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Description

　　最近，佳佳迷上了一款好玩的小游戏：antbuster。游戏规则非常简单：在一张地图上，左上角是蚂蚁窝，右
下角是蛋糕，蚂蚁会源源不断地从窝里爬出来，试图把蛋糕搬回蚂蚁窝。而你的任务，就是用原始资金以及杀蚂蚁
获得的奖金造防御塔，杀掉这些试图跟你抢蛋糕的蚂蚁~下附一张游戏截图：

#include <bits/stdc++.h>

const int MAXN=10;
const int INF=0x7FFFFFFF;

struct Ant{
Ant();
int x;
int y;
int lx;
int ly;
int HP;
int age;
int lvl;
int mxHP;
void Move();
void NormalMove(int);
void SpecialMove(int);
bool CheckAvailable(int,int);
};

struct Tower{
int x;
int y;
Tower();
void Fire();
};

const int dx[]={0,1,0,-1};
const int dy[]={1,0,-1,0};

int n;
int m;
int t;
int clk;
int spn;
bool END;
int s,d,r;
Ant* cakeCarrier;
int sign[MAXN][MAXN];
bool visited[MAXN][MAXN];

std::list<Ant> ants;
std::list<Tower> towers;

void Print();
int Sqr(int);
void CheckEnd();
void OneSecond();
void UpdateAge();
void CleanDeath();
void Initialize();
double Sqr(double);
void IncreaseSignal();
void DecreaseSignal();
bool CheckAvailable(int,int);
int SqrEucDis(int,int,int,int);
bool Cross(double,double,double,int,int);
bool InSegment(int,int,int,int,int,int);

int main(){
Initialize();
while((!END)&&(++clk<=t))
OneSecond();
Print();
return 0;
}

void OneSecond(){
if(ants.size()<6&&CheckAvailable(0,0))
ants.push_back(Ant());
IncreaseSignal();
for(std::list<Ant>::iterator i=ants.begin();i!=ants.end();++i){
i->Move();
}
if(cakeCarrier==NULL){
for(std::list<Ant>::iterator i=ants.begin();i!=ants.end();++i){
if(i->x==n&&i->y==m){
cakeCarrier=&(*i);
i->HP=std::min(i->mxHP,i->HP+i->mxHP/2);
}
}
}
for(std::list<Tower>::iterator i=towers.begin();i!=towers.end();++i){
i->Fire();
}
CleanDeath();
CheckEnd();
if(END)
return;
DecreaseSignal();
UpdateAge();
}

void Tower::Fire(){
Ant* target=NULL;
int mindis=INF;
for(std::list<Ant>::iterator i=ants.begin();i!=ants.end();++i){
int d=SqrEucDis(this->x,this->y,i->x,i->y);
if(d<=Sqr(r)){
if(cakeCarrier==&(*i)){
target=&(*i);
break;
}
else if(d<mindis){
mindis=d;
target=&(*i);
}
}
}
if(target==NULL)
return;
double dx=this->x-target->x;
double dy=this->y-target->y;
double k=dy/dx;
double b=this->y-k*this->x;
for(std::list<Ant>::iterator i=ants.begin();i!=ants.end();++i){
if(dx==0){
if(this->x==i->x&&InSegment(this->x,this->y,target->x,target->y,i->x,i->y)&&SqrEucDis(this->x,this->y,i->x,i->y)<=SqrEucDis(this->x,this->y,target->x,target->y)){
i->HP-=d;
}
}
else{
if(Cross(k,-1.0,b,i->x,i->y)&&InSegment(this->x,this->y,target->x,target->y,i->x,i->y)&&SqrEucDis(this->x,this->y,i->x,i->y)<=SqrEucDis(this->x,this->y,target->x,target->y)){
i->HP-=d;
}
}
}
}

void CheckEnd(){
if(cakeCarrier!=NULL&&cakeCarrier->x==0&&cakeCarrier->y==0)
END=true;
}

void Ant::Move(){
int maxSignal=-INF,dir=-1;
for(int i=0;i<4;i++){
if(this->CheckAvailable(this->x+dx[i],this->y+dy[i])&&maxSignal<sign[this->x+dx[i]][this->y+dy[i]]){
maxSignal=sign[this->x+dx[i]][this->y+dy[i]];
}
}
for(int i=0;i<4;i++){
if(this->CheckAvailable(this->x+dx[i],this->y+dy[i])&&maxSignal==sign[this->x+dx[i]][this->y+dy[i]]){
dir=i;
break;
}
}
if((this->age+1)%5!=0||dir==-1)
this->NormalMove(dir);
else
this->SpecialMove(dir);
}

void Ant::NormalMove(int dir){
if(dir==-1){
this->lx=this->x;
this->ly=this->y;
return;
}
else{
this->lx=this->x;
this->ly=this->y;
visited[this->x][this->y]=false;
this->x+=dx[dir];
this->y+=dy[dir];
visited[this->x][this->y]=true;
}
}

void Ant::SpecialMove(int dir){
dir=(dir-1+4)%4;
while(!this->CheckAvailable(this->x+dx[dir],this->y+dy[dir]))
dir=(dir-1+4)%4;
this->NormalMove(dir);
}

void Initialize(){
scanf("%d%d",&n,&m);
scanf("%d%d%d",&s,&d,&r);
for(int i=0;i<s;i++)
towers.push_back(Tower());
scanf("%d",&t);
}

void CleanDeath(){
std::list<Ant>::iterator i=ants.begin();
std::list<Ant>::iterator tmp;
while(i!=ants.end()){
if(i->HP<0){
if(cakeCarrier==&(*i))
cakeCarrier=NULL;
visited[i->x][i->y]=false;
tmp=i;
++i;
ants.erase(tmp);
}
else
++i;
}
}

void DecreaseSignal(){
for(int i=0;i<=n;i++){
for(int j=0;j<=m;j++){
if(sign[i][j]>0){
--sign[i][j];
}
}
}
}

void UpdateAge(){
for(std::list<Ant>::iterator i=ants.begin();i!=ants.end();++i){
i->age++;
}
}

void IncreaseSignal(){
for(std::list<Ant>::iterator i=ants.begin();i!=ants.end();++i){
if(cakeCarrier==&(*i))
sign[i->x][i->y]+=5;
else
sign[i->x][i->y]+=2;
}
}

Ant::Ant(){
this->lvl=spn/6+1;
this->HP=this->mxHP=int(4*pow(1.1,this->lvl));
this->age=0;
this->x=this->y=this->lx=this->ly=0;
visited[0][0]=true;
spn++;
}

Tower::Tower(){
scanf("%d%d",&this->x,&this->y);
visited[this->x][this->y]=true;
}

void Print(){
if(END)
printf("Game over after %d seconds\n",clk);
else
puts("The game is going on");
printf("%d\n",int(ants.size()));
for(std::list<Ant>::iterator i=ants.begin();i!=ants.end();++i){
printf("%d %d %d %d %d\n",i->age,i->lvl,i->HP,i->x,i->y);
}
}

inline int Sqr(int x){
return x*x;
}

inline double Sqr(double x){
return x*x;
}

inline int SqrEucDis(int x1,int y1,int x2,int y2){
return Sqr(x1-x2)+Sqr(y1-y2);
}

inline bool Cross(double a,double b,double c,int x,int y){
return Sqr(a)+Sqr(b)>Sqr(a*x+b*y+c)*4;
}

inline bool CheckAvailable(int x,int y){
return x>=0&&y>=0&&x<=n&&y<=m&&!visited[x][y];
}

inline bool InSegment(int x1,int y1,int x2,int y2,int x,int y){
int maxx=std::max(x1,x2);
int minx=std::min(x1,x2);
int maxy=std::max(y1,y2);
int miny=std::min(y1,y2);
return minx<=x&&x<=maxx&&miny<=y&&y<=maxy;
}

inline bool Ant::CheckAvailable(int x,int y){
return !(x<0||y<0||x>n||y>m||visited[x][y]||(this->lx==x&&this->ly==y));
}

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