题目链接:https://vjudge.net/problem/UVA-201
题目翻译摘自《算法禁赛入门经典》
有 n 行 n 列(2 ≤ n ≤ 9)的小黑点,还有 m 条线段连接其中的一些黑点。统计这些线段连成 了多少个正方形(每种边长分别统计)。 行从上到下编号为 1~n,列从左到右编号为 1~n。边用 H i j 和 V i j 表示,分别代表边 (i, j)-(i, j + 1) 和 (i, j)-(i + 1, j)。
1 #include <bits/stdc++.h> 2 using namespace std; 3 4 #define INIT() ios::sync_with_stdio(false);cin.tie(0);cout.tie(0); 5 #define Rep(i,n) for (int i = 0; i < (n); ++i) 6 #define For(i,s,t) for (int i = (s); i <= (t); ++i) 7 #define rFor(i,t,s) for (int i = (t); i >= (s); --i) 8 #define ForLL(i, s, t) for (LL i = LL(s); i <= LL(t); ++i) 9 #define rForLL(i, t, s) for (LL i = LL(t); i >= LL(s); --i) 10 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i) 11 #define rforeach(i,c) for (__typeof(c.rbegin()) i = c.rbegin(); i != c.rend(); ++i) 12 13 #define pr(x) cout << #x << " = " << x << " " 14 #define prln(x) cout << #x << " = " << x << endl 15 16 #define LOWBIT(x) ((x)&(-x)) 17 18 #define ALL(x) x.begin(),x.end() 19 #define INS(x) inserter(x,x.begin()) 20 21 #define ms0(a) memset(a,0,sizeof(a)) 22 #define msI(a) memset(a,inf,sizeof(a)) 23 #define msM(a) memset(a,-1,sizeof(a)) 24 25 #define MP make_pair 26 #define PB push_back 27 #define ft first 28 #define sd second 29 30 template<typename T1, typename T2> 31 istream &operator>>(istream &in, pair<T1, T2> &p) { 32 in >> p.first >> p.second; 33 return in; 34 } 35 36 template<typename T> 37 istream &operator>>(istream &in, vector<T> &v) { 38 for (auto &x: v) 39 in >> x; 40 return in; 41 } 42 43 template<typename T1, typename T2> 44 ostream &operator<<(ostream &out, const std::pair<T1, T2> &p) { 45 out << "[" << p.first << ", " << p.second << "]" << "\n"; 46 return out; 47 } 48 49 inline int gc(){ 50 static const int BUF = 1e7; 51 static char buf[BUF], *bg = buf + BUF, *ed = bg; 52 53 if(bg == ed) fread(bg = buf, 1, BUF, stdin); 54 return *bg++; 55 } 56 57 inline int ri(){ 58 int x = 0, f = 1, c = gc(); 59 for(; c<48||c>57; f = c==‘-‘?-1:f, c=gc()); 60 for(; c>47&&c<58; x = x*10 + c - 48, c=gc()); 61 return x*f; 62 } 63 64 template<class T> 65 inline string toString(T x) { 66 ostringstream sout; 67 sout << x; 68 return sout.str(); 69 } 70 71 typedef long long LL; 72 typedef unsigned long long uLL; 73 typedef pair< double, double > PDD; 74 typedef pair< int, int > PII; 75 typedef pair< int, PII > PIPII; 76 typedef pair< string, int > PSI; 77 typedef pair< int, PSI > PIPSI; 78 typedef set< int > SI; 79 typedef set< PII > SPII; 80 typedef vector< int > VI; 81 typedef vector< VI > VVI; 82 typedef vector< PII > VPII; 83 typedef map< int, int > MII; 84 typedef map< int, string > MIS; 85 typedef map< int, PII > MIPII; 86 typedef map< PII, int > MPIII; 87 typedef map< string, int > MSI; 88 typedef map< string, string > MSS; 89 typedef map< PII, string > MPIIS; 90 typedef map< PII, PII > MPIIPII; 91 typedef multimap< int, int > MMII; 92 typedef multimap< string, int > MMSI; 93 //typedef unordered_map< int, int > uMII; 94 typedef pair< LL, LL > PLL; 95 typedef vector< LL > VL; 96 typedef vector< VL > VVL; 97 typedef priority_queue< int > PQIMax; 98 typedef priority_queue< int, VI, greater< int > > PQIMin; 99 const double EPS = 1e-6; 100 const LL inf = 0x7fffffff; 101 const LL infLL = 0x7fffffffffffffffLL; 102 const LL mod = 1e9 + 7; 103 const int maxN = 1e4 + 7; 104 const LL ONE = 1; 105 const LL evenBits = 0xaaaaaaaaaaaaaaaa; 106 const LL oddBits = 0x5555555555555555; 107 108 int T, n, m; 109 int A[23][23], rowPreSum[23][23], colPreSum[23][23]; 110 MII sqr; // size->cnt 111 112 int main(){ 113 //freopen("MyOutput.txt","w",stdout); 114 //freopen("input.txt","r",stdin); 115 //INIT(); 116 while(cin >> n >> m) { 117 ms0(A); 118 ms0(rowPreSum); 119 ms0(colPreSum); 120 sqr.clear(); 121 n = 2 * n - 1; 122 Rep(i, m) { 123 string str; 124 int x, y; 125 cin >> str >> x >> y; 126 x = 2 * x - 1; 127 y = 2 * y - 1; 128 if(str == "H") For(j, y, y + 2) A[x][j] = 1; 129 else For(j, y, y + 2) A[j][x] = 1; 130 } 131 // 计算矩阵的行列前缀和 132 For(i, 1, n) { 133 For(j, 1, n) { 134 rowPreSum[i][j] += rowPreSum[i][j - 1] + A[i][j]; 135 colPreSum[i][j] += colPreSum[i][j - 1] + A[j][i]; 136 } 137 } 138 139 // 枚举所有正方形对角点对 140 For(i, 1, n) { 141 For(j, 1, n) { 142 For(k, 2, n) { 143 if(i + k > n || j + k > n) break; 144 if(rowPreSum[i][j + k] - rowPreSum[i][j - 1] == k + 1 && 145 rowPreSum[i][j + k] - rowPreSum[i][j - 1] == colPreSum[j][i + k] - colPreSum[j][i - 1] && 146 colPreSum[j][i + k] - colPreSum[j][i - 1] == rowPreSum[i + k][j + k] - rowPreSum[i + k][j - 1] && 147 rowPreSum[i + k][j + k] - rowPreSum[i + k][j - 1] == colPreSum[j + k][i + k] - colPreSum[j + k][i - 1] 148 ) ++sqr[(k + 1) / 2]; 149 } 150 } 151 } 152 153 if(T++) printf("\n**********************************\n\n"); 154 printf("Problem #%d\n\n", T); 155 if(sqr.empty()) printf("No completed squares can be found.\n"); 156 else foreach(i, sqr) printf("%d square (s) of size %d\n", i->sd, i->ft); 157 } 158 return 0; 159 }
原文:https://www.cnblogs.com/zaq19970105/p/11032093.html