POJ 2033 alpha code 的译码数目

#include<iostream>#include<cstring>#include<fstream>using namespace std;static int f[10001];static char a[10002];int main(){while (cin >> (a + 1)){if (a[1] == '0')break;int n = strlen(a + 1);int i;f[0] = 1;f[1] = 1;for (i = 2; i <= n; i++){f[i] = 0;if (a[i] != '0')f[i] = f[i - 1];if (a[i - 1] == '1' || (a[i -1] == '2' && a[i] <= '6')){f[i] += f[i - 2];}}cout << f[n] << "\n";}return 0;}

[a, z]===>[1, 26]

典型的动态规划，递推关系比较容易找寻。

f[i]  [1, i] 段的数目。

另外就是 ‘0’ 和 0 程序书写时易出错。