第三题100 public long GetNumOfExpress(String express, boolean desired) { // write code here if (express==null || express.length()==0 || !isValid(express.toCharArray())){ return 0; } char[] str = express.toCharArray(); int len = str.length; long[][] dpTrue = new long[len][len]; long[][] dpFalse = new long[len][len]; if (str[0]=='0'){ dpTrue[0][0] = 0; dpFalse[0][0] = 1; } else { dpTrue[0][0] = 1; dpFalse[0][0] = 0; } // 区间dp for (int j=0;j<len>=0;i-=2){ for (int k=i+1;k</len>