.

Author: hqztrue

0701-0800/711. Number of Distinct Islands II 40ms.cpp

@@ -0,0 +1,81 @@
+const int N=55,P=1000000007,mul=173;
+typedef long long ll;
+size_t get_hash(vector<int> &v){
+	static size_t P=1000000007,M=173;
+	int n=v.size(); size_t res=0;
+	/*unordered_set<int> S;
+	for (int i=0;i<n;++i)S.insert(v[i]);
+	for (int i=0;i<S.bucket_count();++i){
+		vector<int> u(S.begin(i),S.end(i)); sort(u.begin(),u.end());
+		for (int j=0;j<u.size();++j)res=((long long)res*M+u[j])%P;
+	}*/
+	sort(v.begin(),v.end());
+    for (int j=0;j<v.size();++j)res=((long long)res*M+v[j])%P;
+	return ((long long)res*M+n)%P;
+}
+struct point{
+	int x,y;
+}q[N*N];
+int pw[N*N];
+class Solution {
+public:
+	int numDistinctIslands2(vector<vector<int>>& grid) {
+		int n=grid.size(),m=grid[0].size(),ans=0;
+		unordered_set<int> S;
+		for (int i=0;i<n;++i)
+			for (int j=0;j<m;++j)
+				if (grid[i][j]){
+					int h=0,t=1,xmin=i,xmax=i,ymin=j,ymax=j;
+					q[0].x=i; q[0].y=j; grid[i][j]=0;
+					while (h<t){
+						point &p=q[h++]; int i=p.x,j=p.y;
+						if (i+1<n&&grid[i+1][j]){
+							q[t].x=i+1; q[t++].y=j;
+							grid[i+1][j]=0; if (i+1>xmax)xmax=i+1;
+						}
+						if (i-1>=0&&grid[i-1][j]){
+							q[t].x=i-1; q[t++].y=j;
+							grid[i-1][j]=0; if (i-1<xmin)xmin=i-1;
+						}
+						if (j+1<m&&grid[i][j+1]){
+							q[t].x=i; q[t++].y=j+1;
+							grid[i][j+1]=0; if (j+1>ymax)ymax=j+1;
+						}
+						if (j-1>=0&&grid[i][j-1]){
+							q[t].x=i; q[t++].y=j-1;
+							grid[i][j-1]=0; if (j-1<ymin)ymin=j-1;
+						}
+					}
+					for (int k=0;k<t;++k)q[k].x-=xmin,q[k].y-=ymin;
+					int W=xmax-xmin+1,H=ymax-ymin+1,tmp,h1=1;
+					//vector<int> v;
+					for (int I=0;I<=1;++I){
+						for (int J=0;J<4;++J){
+							int h=0;
+							for (int k=0;k<t;++k)h=(h+pw[q[k].x*H+q[k].y])%P;
+							h=((ll)h*mul+W)%P; h=((ll)h*mul+H)%P;
+							h1=(ll)h1*h; //v.push_back(h);
+							if (J<4){
+								for (int k=0;k<t;++k)tmp=W-1-q[k].x,q[k].x=q[k].y,q[k].y=tmp;
+								swap(W,H);
+							}
+						}
+						if (!I)for (int k=0;k<t;++k)q[k].x=W-1-q[k].x;
+					}
+					//h1=get_hash(v);
+					if (S.find(h1)==S.end())S.insert(h1),++ans;
+				}
+		return ans;
+	}
+};
+
+//IO
+int _IO=[](){
+	ios::sync_with_stdio(0);
+	cin.tie(0); //cout.tie(0);
+	for (int i=0,j=1;i<N*N;++i)
+		pw[i]=j,j=(ll)j*mul%P;
+	return 0;
+}();
+
+

0701-0800/711. Number of Distinct Islands II.pdf

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+divide and conquer. put all even numbers on the left half, and all odd numbers on the right half, then recurse. O(n).
+

0701-0800/711. Number of Distinct Islands II.txt

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+monotone stack. O(n).
+

0901-1000/932. Beautiful Array.txt

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+const int N=100005;
+void radix_sort(int A[],int l,int r){  //a[i]>=0
+	//const int base=65535,W=16;
+	const int base=2047,W=11;
+	//const int base=255,W=8;
+	const int T=(32-1)/W+1;
+	static int B[N],s[base+1];
+	A+=l-1;r-=l-1;l=1;
+	int *a=A,*b=B,x=0;
+	for (int i1=1;i1<=T;++i1){
+		for (int i=0;i<=base;++i)s[i]=0;
+		for (int i=1;i<=r;++i)++s[a[i]>>x&base];
+		for (int i=1;i<=base;++i)s[i]+=s[i-1];
+		for (int i=r;i>=1;--i)b[s[a[i]>>x&base]--]=a[i];
+		int *tmp=a;a=b;b=tmp;
+		x+=W;
+	}
+	if (a!=A)for (int i=1;i<=r;++i)A[i]=a[i];
+}
+class Solution {
+public:
+	int maxBoxesInWarehouse(vector<int>& b, vector<int>& w) {
+		int ans=0,n=b.size(),p1=0,p2=w.size()-1;
+		radix_sort(&b[0],0,n-1);
+		for (int i=n-1;i>=0&&p1<=p2;--i){
+			if (b[i]<=w[p1])++p1,++ans;
+			else if (b[i]<=w[p2])--p2,++ans;
+		}
+		return ans;
+	}
+};
+
+//IO
+int _IO=[](){
+	ios::sync_with_stdio(0);
+	cin.tie(0); //cout.tie(0);
+	return 0;
+}();
+
+

0901-1000/962. Maximum Width Ramp.txt

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+1. counting the number of occurrences of each variable. O(n).
+2. random evaluation. O(n).
+

1401-1500/1494. Parallel Courses II.txt

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+O(n).
+

1501-1600/1564. Put Boxes Into the Warehouse I.pdf

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+greedily increment the rightmost character. O(n).
+

1501-1600/1564. Put Boxes Into the Warehouse I.txt

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+prefix sum and suffix sum. O(n).
+

1501-1600/1580. Put Boxes Into the Warehouse II 160ms.cpp

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+sort by minimum-actual in decreasing order, then greedily complete the rightmost task at the end. O(sort(n)).
+