Spreadsheet Calculator 电子表格计算器 (Uva 215)
原题:https://uva.onlinejudge.org/external/2/215.pdf
有一个M x N的表格，每个单元格是个数字或者表达式。表达式由单元格编号和＋ － 号组成
输出单元格的结果
思路：用dfs判断有向图环的问题
1 #include <iostream> 2 #include <cstdio> 3 #include <cstdlib> 4 #include <utility> 5 #include <cstring> 6 #include <sstream> 7 8 using namespace std; 9 const int MAXR = 20 + 2, MAXC = 10 + 2; 10 string sheet[MAXR][MAXC]; 11 int r, c; 12 bool hasCircle[MAXR][MAXC], f[MAXR][MAXC], ok; 13 14 bool isNumber(int x, int y) { 15 string s = sheet[x][y]; 16 int l = s.size(); 17 if (isalpha(s[0])) return false; 18 for (int i = 0; i < l; i++) { 19 if (i != 0 && !isdigit(s[i])) return false; 20 } 21 return true; 22 } 23 24 void dfs(int x, int y) { 25 if (hasCircle[x][y] || isNumber(x, y)) return; 26 if (f[x][y]) {hasCircle[x][y] = 1; return; } 27 f[x][y] = 1; 28 string s = sheet[x][y]; 29 char sign; int ans = 0, right, len = sheet[x][y].size(), i = 0; 30 while (i < len) { 31 sign = '+'; 32 if (s[i] == '-' || s[i] == '+') { 33 sign = s[i]; 34 i++; 35 } 36 if (isalpha(s[i])) { 37 int nx = s[i] - 'A', ny = s[i + 1] - '0'; 38 i += 2; 39 dfs(nx, ny); 40 if (hasCircle[nx][ny]) { 41 hasCircle[x][y] = 1; 42 return; 43 } 44 right = stoi(sheet[nx][ny]); 45 } 46 else { 47 int j = i + 1; 48 while (j < len && isdigit(s[j])) j++; 49 right = stoi(s.substr(i, j - i)); 50 i = j; 51 } 52 ans += right * ((sign == '+') ? 1 : -1); 53 } 54 stringstream ss; ss << ans; 55 ss >> sheet[x][y]; 56 } 57 58 int main() { 59 freopen("in", "r", stdin); 60 //freopen("out", "w", stdout); 61 while (scanf("%d%d", &r, &c) == 2 && r) { 62 memset(f, 0, sizeof(f)); 63 memset(hasCircle, 0, sizeof(hasCircle)); 64 ok = 1; 65 for (int i = 0; i < r; i++) 66 for (int j = 0; j < c; j++) 67 cin >> sheet[i][j]; 68 69 for (int i = 0; i < r; i++) 70 for (int j = 0; j < c; j++) { 71 if (!f[i][j]) 72 dfs(i, j); 73 if (hasCircle[i][j]) ok = 0; 74 } 75 if (!ok) { 76 for (int i = 0; i < r; i++) 77 for (int j = 0; j < c; j++) 78 if (hasCircle[i][j]) cout << char(i + 'A') << j << ": " << sheet[i][j] << endl; 79 } 80 else { 81 putchar(' '); 82 for (int i = 0; i < c; i++) printf(" %d", i); 83 putchar('\n'); 84 for (int i = 0; i < r; i++) { 85 printf("%c", i + 'A'); 86 for (int j = 0; j < c; j++) { 87 for (int k = 0; k < 6 - sheet[i][j].size(); k++) putchar(' '); 88 cout << sheet[i][j]; 89 } 90 putchar('\n'); 91 } 92 } 93 putchar('\n'); 94 } 95 96 return 0; 97 }
