La Salle-Pui Ching Programming Challenge 培正喇沙編程挑戰賽 2017
A Ambiguous Dates
贪心，从小到大取日期
#include
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define Fork(i,k,n) for(int i=k;i<=n;i++)
#define ForkD(i,k,n) for(int i=n;i>=k;i--)
#define Rep(i,n) for(int i=0;i
#define ForD(i,n) for(int i=n;i;i--)
#define RepD(i,n) for(int i=n;i>=0;i--)
#define Forp(x) for(int p=pre[x];p;p=next[p])
#define Forpiter(x) for(int &p=iter[x];p;p=next[p])
#define Lson (o<<1)
#define Rson ((o<<1)+1)
#define MEM(a) memset(a,0,sizeof(a));
#define MEMI(a) memset(a,0x3f,sizeof(a));
#define MEMi(a) memset(a,128,sizeof(a));
#define MEMx(a,b) memset(a,b,sizeof(a));
#define INF (0x3f3f3f3f)
#define F (1000000007)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define vi vector
#define pi pair
#define PRi2D(a,n,m) For(i,n) { \
For(j,m-1) cout<' ' ;\
cout<#pragma comment(linker, "/STACK:102400000,102400000")
#define ALL(x) (x).begin(),(x).end()
#define gmax(a,b) a=max(a,b);
#define gmin(a,b) a=min(a,b);
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return ((a-b)%F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
inline int read()
{
int x=0,f=1; char ch=getchar();
while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
return x*f;
}
#define MAXN (123456)
ll d[MAXN];
ll Abs(ll x){return max(x,-x);}
int main()
{
// freopen("A.in","r",stdin);
// freopen(".out","w",stdout);
int n=read();
For(i,n) d[i]=read();
ll ans=0;
sort(d+1,d+1+n);ll c=0;
For(i,n) {
ll p=d[i];
if (p>i) {
ans+=min((ll)n-i,d[i]-i);
}
}
cout<<2*ans<return 0;
}
B Bacteria Experiment
求树直径
#include
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define Fork(i,k,n) for(int i=k;i<=n;i++)
#define ForkD(i,k,n) for(int i=n;i>=k;i--)
#define Rep(i,n) for(int i=0;i
#define ForD(i,n) for(int i=n;i;i--)
#define RepD(i,n) for(int i=n;i>=0;i--)
#define Forp(x) for(int p=pre[x];p;p=next[p])
#define Forpiter(x) for(int &p=iter[x];p;p=next[p])
#define Lson (o<<1)
#define Rson ((o<<1)+1)
#define MEM(a) memset(a,0,sizeof(a));
#define MEMI(a) memset(a,0x3f,sizeof(a));
#define MEMi(a) memset(a,128,sizeof(a));
#define MEMx(a,b) memset(a,b,sizeof(a));
#define INF (0x3f3f3f3f)
#define F (1000000007)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define vi vector
#define pi pair
#define PRi2D(a,n,m) For(i,n) { \
For(j,m-1) cout<' ' ;\
cout<#pragma comment(linker, "/STACK:102400000,102400000")
#define ALL(x) (x).begin(),(x).end()
#define gmax(a,b) a=max(a,b);
#define gmin(a,b) a=min(a,b);
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return ((a-b)%F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
inline int read()
{
int x=0,f=1; char ch=getchar();
while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
return x*f;
}
#define MAXN (912345)
vi e[MAXN];
int dep[MAXN]={};
void dfs(int x,int fa) {
dep[x]=dep[fa]+1;
for(auto v:e[x]) {
if (v!=fa) dfs(v,x);
}
}
int main()
{
// freopen("B.in","r",stdin);
// freopen(".out","w",stdout);
int n=read();
For(i,n-1) {
int x=read(),y=read();
e[x].pb(y);e[y].pb(x);
}
dfs(1,0);
int mx=max_element(dep+1,dep+1+n)-dep;
MEM(dep);
dfs(mx,0);
int l=*max_element(dep+1,dep+1+n);
int ans=0,dis=1; --l;
while(dis1;
cout<return 0;
}
C Cheering
签到
#include
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define Fork(i,k,n) for(int i=k;i<=n;i++)
#define ForkD(i,k,n) for(int i=n;i>=k;i--)
#define Rep(i,n) for(int i=0;i
#define ForD(i,n) for(int i=n;i;i--)
#define RepD(i,n) for(int i=n;i>=0;i--)
#define Forp(x) for(int p=pre[x];p;p=next[p])
#define Forpiter(x) for(int &p=iter[x];p;p=next[p])
#define Lson (o<<1)
#define Rson ((o<<1)+1)
#define MEM(a) memset(a,0,sizeof(a));
#define MEMI(a) memset(a,0x3f,sizeof(a));
#define MEMi(a) memset(a,128,sizeof(a));
#define MEMx(a,b) memset(a,b,sizeof(a));
#define INF (0x3f3f3f3f)
#define F (1000000007)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define vi vector
#define pi pair
#define PRi2D(a,n,m) For(i,n) { \
For(j,m-1) cout<' ' ;\
cout<#pragma comment(linker, "/STACK:102400000,102400000")
#define ALL(x) (x).begin(),(x).end()
#define gmax(a,b) a=max(a,b);
#define gmin(a,b) a=min(a,b);
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return ((a-b)%F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
inline int read()
{
int x=0,f=1; char ch=getchar();
while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
return x*f;
}
char s[12345];
int main()
{
// freopen("E.in","r",stdin);
// freopen(".out","w",stdout);
cin>>s;
int n=strlen(s),p=0;
Rep(i,n-2) {
if (s[i]=='L'&&s[i+1]=='S'&&s[i+2]=='C') ++p;
}
Rep(i,n-3) {
if (s[i]=='P'&&s[i+1]=='C'&&s[i+2]=='M'&&s[i+3]=='S') --p;
}
if (!p) puts("Tie");else puts(p>0?"LSC":"PCMS");
return 0;
}
H Hit!
给2个圆保证存在不为0的公共部分，求公共部分的任意一个点
分2种情况，内含，内切（此时解取1个圆的圆心），相交圆心连线上的一个点。
#include
#define ForD(i,n) for(int i=n;i;i--)
#define ForkD(i,k,n) for(int i=n;i>=k;i--)
#define RepD(i,n) for(int i=n;i>=0;i--)
#define Forp(x) for(int p=Pre[x];p;p=Next[p])
#define Forpiter(x) for(int &p=iter[x];p;p=Next[p])
#define Lson (o<<1)
#define Rson ((o<<1)+1)
#define MEM(a) memset(a,0,sizeof(a));
#define MEMI(a) memset(a,127,sizeof(a));
#define MEMi(a) memset(a,128,sizeof(a));
#define INF (2139062143)
#define F (100000007)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define vi vector
#define pi pairreturn 0; else return x<0 ? -1 : 1;
}
ld PI = 3.141592653589793238462643383;
class P{
public:
double x,y;
P(double x=0,double y=0):x(x),y(y){}
friend ld dis2(P A,P B){return sqr(A.x-B.x)+sqr(A.y-B.y); }
friend ld Dot(P A,P B) {return A.x*B.x+A.y*B.y; }
friend ld Length(P A) {return sqrt(Dot(A,A)); }
friend ld Angle(P A,P B) {
if (dcmp(Dot(A,A))==0||dcmp(Dot(B,B))==0||dcmp(Dot(A-B,A-B))==0) return 0;
return acos(max((ld)-1.0, min((ld)1.0, Dot(A,B) / Length(A) / Length(B) )) );
}
friend P operator- (P A,P B) { return P(A.x-B.x,A.y-B.y); }
friend P operator+ (P A,P B) { return P(A.x+B.x,A.y+B.y); }
friend P operator* (P A,double p) { return P(A.x*p,A.y*p); }
friend P operator/ (P A,double p) { return P(A.x/p,A.y/p); }
friend bool operator< (const P& a,const P& b) {return dcmp(a.x-b.x)<0 ||(dcmp(a.x-b.x)==0&& dcmp(a.y-b.y)<0 );}
};
P read_point() {
P a;
scanf("%lf%lf",&a.x,&a.y);
return a;
}
bool operator==(const P& a,const P& b) {
return dcmp(a.x-b.x)==0 && dcmp(a.y-b.y) == 0;
}
typedef P V;
double Cross(V A,V B) {return A.x*B.y - A.y*B.x;}
double DistanceToLine(P p,P A,P B) {
V v1 = B-A, v2 = p-A;
return fabs(Cross(v1,v2))/Length(v1);
}
P GetLineProjection(P p,P A,P B) {
V v=B-A;
return A+v*(Dot(v,p-A)/Dot(v,v));
}
struct C{
P c;
double r,x,y;
C(){}
C(P c,double r):c(c),r(r),x(c.x),y(c.y){}
P point(double a) {
return P(c.x+cos(a)*r,c.y+sin(a)*r);
}
};
struct Line{
P p;
V v;
double ang;
Line(){}
Line(P p,V v):p(p),v(v) {ang=atan2(v.y,v.x); }
bool operator<(const Line & L) const {
return angdouble a) {
return p+v*a;
}
};
int getLineCircleIntersection(Line L,C cir,double &t1,double &t2,vector & sol) {
if (dcmp(DistanceToLine(cir.c,L.p,L.p+L.v)-cir.r)==0) {
P A=GetLineProjection(cir.c,L.p,L.p+L.v);
sol.pb(A);
t1 = (A-L.p).x / L.v.x;
return 1;
}
double a = L.v.x, b = L.p.x - cir.c.x, c = L.v.y, d= L.p.y - cir.c.y;
double e = a*a+c*c, f = 2*(a*b + c*d), g = b*b+d*d-cir.r*cir.r;
double delta = f*f - 4*e*g;
if (dcmp(delta)<0) return 0;
else if (dcmp(delta)==0) {
t1 = t2 = -f / (2*e); sol.pb(L.point(t1));
return 1;
}
t1 = (-f - sqrt(delta)) / (2*e); sol.pb(L.point(t1));
t2 = (-f + sqrt(delta)) / (2*e); sol.pb(L.point(t2));
return 2;
}
double angle(V v) {return atan2(v.y,v.x);}
int getCircleCircleIntersection(C C1,C C2,vector& sol) {
double d = Length(C1.c-C2.c);
if (dcmp(d)==0) {
if (dcmp(C1.r - C2.r)==0) return -1; //2圆重合
return 0;
}
if (dcmp(C1.r+C2.r-d)<0) return 0;
if (dcmp(fabs(C1.r-C2.r)-d)>0) return 0;
double a = angle(C2.c-C1.c);
double da = acos((C1.r*C1.r+d*d - C2.r*C2.r)/ (2*C1.r*d));
P p1 = C1.point(a-da), p2 = C1.point(a+da);
sol.pb(p1);
if (p1==p2) return 1;
sol.pb(p2);
return 2;
}
int main()
{
// freopen("H.in","r",stdin);
// freopen(".out","w",stdout);
double x,y,r,a,b,c;
cin>>x>>y>>r>>a>>b>>c;
P p1=P(x,y),p2=P(a,b);
C c0=C(p1,r),c1=C(p2,c);
vector sol;
if (getCircleCircleIntersection(c0,c1,sol)>=2) {
printf("%.10lf %.10lf\n",(sol[0].x+sol[1].x)/2 ,(sol[0].y+sol[1].y)/2 );
}
else if (rprintf("%.10lf %.10lf\n",x,y );
}
else {
printf("%.10lf %.10lf\n",a,b );
}
return 0;
}
Inverted Signs
显然翻转一段只会影响2端点的贡献
#include
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define Fork(i,k,n) for(int i=k;i<=n;i++)
#define ForkD(i,k,n) for(int i=n;i>=k;i--)
#define Rep(i,n) for(int i=0;i
#define ForD(i,n) for(int i=n;i;i--)
#define RepD(i,n) for(int i=n;i>=0;i--)
#define Forp(x) for(int p=pre[x];p;p=next[p])
#define Forpiter(x) for(int &p=iter[x];p;p=next[p])
#define Lson (o<<1)
#define Rson ((o<<1)+1)
#define MEM(a) memset(a,0,sizeof(a));
#define MEMI(a) memset(a,0x3f,sizeof(a));
#define MEMi(a) memset(a,128,sizeof(a));
#define MEMx(a,b) memset(a,b,sizeof(a));
#define INF (0x3f3f3f3f)
#define F (1000000007)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define vi vector
#define pi pair
#define PRi2D(a,n,m) For(i,n) { \
For(j,m-1) cout<' ' ;\
cout<#pragma comment(linker, "/STACK:102400000,102400000")
#define ALL(x) (x).begin(),(x).end()
#define gmax(a,b) a=max(a,b);
#define gmin(a,b) a=min(a,b);
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return ((a-b)%F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
inline int read()
{
int x=0,f=1; char ch=getchar();
while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
return x*f;
}
#define MAXN (1123456)
ll h[MAXN],s[MAXN];
ll Abs(ll x){return max(x,-x);}
int main()
{
// freopen("I.in","r",stdin);
// freopen(".out","w",stdout);
int n=read();
For(i,n) h[i]=read();
ll ans=0;
For(i,n-1) ans+=Abs(h[i]-h[i+1]);
s[1]=0;
Fork(i,2,n) {
s[i]=Abs(-h[i]-h[i-1]) - Abs(h[i]-h[i-1]);
s[i]=min(s[i],s[i-1]);
}
ll del=0,pcost=0;
ForD(i,n) {
ll p;
if (i==n) p=0;
else p=Abs(-h[i]-h[i+1]) - Abs(h[i]-h[i+1]);
pcost=min(p,pcost);
del= min (del , pcost+s[i]);
}
cout<return 0;
}
K Knights
四个角无法在第二阶段被其他Knights影响，只能自己覆盖自己。
覆盖了4个角以后能覆盖原图。
#include
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define Fork(i,k,n) for(int i=k;i<=n;i++)
#define ForkD(i,k,n) for(int i=n;i>=k;i--)
#define Rep(i,n) for(int i=0;i
#define ForD(i,n) for(int i=n;i;i--)
#define RepD(i,n) for(int i=n;i>=0;i--)
#define Forp(x) for(int p=pre[x];p;p=next[p])
#define Forpiter(x) for(int &p=iter[x];p;p=next[p])
#define Lson (o<<1)
#define Rson ((o<<1)+1)
#define MEM(a) memset(a,0,sizeof(a));
#define MEMI(a) memset(a,0x3f,sizeof(a));
#define MEMi(a) memset(a,128,sizeof(a));
#define MEMx(a,b) memset(a,b,sizeof(a));
#define INF (0x3f3f3f3f)
#define F (1000000007)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define vi vector
#define pi pair
#define PRi2D(a,n,m) For(i,n) { \
For(j,m-1) cout<' ' ;\
cout<#pragma comment(linker, "/STACK:102400000,102400000")
#define ALL(x) (x).begin(),(x).end()
#define gmax(a,b) a=max(a,b);
#define gmin(a,b) a=min(a,b);
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
ll mul(ll a,ll b){return (a*b)%F;}
ll add(ll a,ll b){return (a+b)%F;}
ll sub(ll a,ll b){return ((a-b)%F+F)%F;}
void upd(ll &a,ll b){a=(a%F+b%F)%F;}
inline int read()
{
int x=0,f=1; char ch=getchar();
while(!isdigit(ch)) {if (ch=='-') f=-1; ch=getchar();}
while(isdigit(ch)) { x=x*10+ch-'0'; ch=getchar();}
return x*f;
}
#define MAXN (123456)
int b[2][2]={};
int main()
{
// freopen("K.in","r",stdin);
// freopen(".out","w",stdout);
int n=read(),m=read(),k=read();
For(i,k) {
int x=read(),y=read();
if ((11continue;
if(1==x&&1==y) b[0][0]=1;
if(1==x&&m==y) b[0][1]=1;
if(n==x&&1==y) b[1][0]=1;
if(n==x&&m==y) b[1][1]=1;
}
if (n==1 &&m==1) {
puts(b[1][1]?"0":"1");
}
else if (n==1) {
cout<<2-b[0][0]-b[0][1]<else if (m==1) {
cout<<2-b[0][0]-b[1][0]<else {
cout<<4-b[0][0]-b[1][0]-b[0][1]-b[1][1]<return 0;
}