先附上自己的写法,运气好的话可以过,运气不好的话超时,这东西也看人品?
1 #pragma comment(linker, "/STACK:1024000000,1024000000") 2 #include<iostream> 3 #include<cstdio> 4 #include<cstring> 5 #include<cmath> 6 #include<math.h> 7 #include<algorithm> 8 #include<queue> 9 #include<set> 10 #include<bitset> 11 #include<map> 12 #include<vector> 13 #include<stdlib.h> 14 using namespace std; 15 #define ll long long 16 #define eps 1e-10 17 #define MOD 1000000007 18 #define N 1000006 19 #define inf 1e12 20 21 struct node{ 22 ll x,y; 23 }e[N],res[N]; 24 ll cmp(node a,node b) 25 { 26 if(a.x==b.x)return a.y<b.y; 27 return a.x<b.x; 28 } 29 ll cross(node a,node b,node c)//向量积 30 { 31 return (a.x-c.x)*(b.y-c.y)-(b.x-c.x)*(a.y-c.y); 32 } 33 ll convex(ll n)//求凸包上的点 34 { 35 sort(e,e+n,cmp); 36 ll m=0,i,j,k; 37 //求得下凸包,逆时针 38 //已知凸包点m个,如果新加入点为i,则向量(m-2,i)必定要在(m-2,m-1)的逆时针方向才符合凸包的性质 39 //若不成立,则m-1点不在凸包上。 40 for(i=0;i<n;i++) 41 { 42 while(m>1&&cross(res[m-1],e[i],res[m-2])<=0)m--; 43 res[m++]=e[i]; 44 } 45 k=m; 46 //求得上凸包 47 for(i=n-2;i>=0;i--) 48 { 49 while(m>k&&cross(res[m-1],e[i],res[m-2])<=0)m--; 50 res[m++]=e[i]; 51 } 52 if(n>1)m--;//起始点重复。 53 return m; 54 } 55 56 long long n,seed; 57 inline long long rand(long long l, long long r) { 58 static long long mo=1e9+7, g=78125; 59 return l+((seed*=g)%=mo)%(r-l+1); 60 } 61 62 int main() 63 { 64 int t; 65 scanf("%d",&t); 66 while(t--){ 67 cin >> n >> seed; 68 for (int i = 0; i < n; i++){ 69 e[i].x = rand(-1000000000, 1000000000), 70 e[i].y = rand(-1000000000, 1000000000); 71 } 72 ll m=convex(n); 73 ll ans=-1; 74 for(ll i=0;i<m;i++){ 75 for(ll j=i+1;j<m;j++){ 76 ll cnt = abs(res[i].x-res[j].x)+abs(res[i].y-res[j].y); 77 ans=max(ans,cnt); 78 } 79 } 80 printf("%I64d\n",ans); 81 82 } 83 return 0; 84 }
官方题解:
1 #include<bitset> 2 #include<map> 3 #include<vector> 4 #include<cstdio> 5 #include<iostream> 6 #include<cstring> 7 #include<string> 8 #include<algorithm> 9 #include<cmath> 10 #include<stack> 11 #include<queue> 12 #include<set> 13 #define inf 0x3f3f3f3f 14 #define mem(a,x) memset(a,x,sizeof(a)) 15 16 using namespace std; 17 18 typedef long long ll; 19 typedef unsigned long long ull; 20 typedef pair<int,int> pii; 21 22 inline int in() 23 { 24 int res=0;char c;int f=1; 25 while((c=getchar())<‘0‘ || c>‘9‘)if(c==‘-‘)f=-1; 26 while(c>=‘0‘ && c<=‘9‘)res=res*10+c-‘0‘,c=getchar(); 27 return res*f; 28 } 29 const int N = 1000003; 30 31 ll a[N][3]; 32 int n; 33 long long seed; 34 inline long long rand(long long l, long long r) { 35 static long long mo=1e9+7, g=78125; 36 return l+((seed*=g)%=mo)%(r-l+1); 37 } 38 int main() { 39 int T; 40 for (scanf("%d", &T);T--;) { 41 cin >> n >> seed; 42 for (int i=0; i<n; i++) 43 a[i][0]=rand(-1000000000, 1000000000), 44 a[i][1]=rand(-1000000000, 1000000000); 45 ll t=0; 46 ll ans=0,mx=-9223372036854775808LL,mn=9223372036854775807LL; 47 for (int s=0; s<(1<<2); s++) { 48 mx=-9223372036854775808LL,mn=9223372036854775807LL; 49 for (int i=0; i<n; i++) { 50 t = 0; 51 for (int j=0; j<2; j++) 52 if ((1<<j) & s) t += a[i][j]; 53 else t -= a[i][j]; 54 mn = min(mn, t); 55 mx = max(mx, t); 56 } 57 ans = max(ans, mx-mn); 58 } 59 printf("%I64d\n", ans); 60 } 61 return 0; 62 }
原文:http://www.cnblogs.com/UniqueColor/p/5188351.html