简单的四则运算.doc

public class clsCalculate /calculate /1+(2+3) * (5+6) - (5-2) / 2 public string CalculateAll(string str) string sall = str.Split(new char ( ); string stmp = ; while (sall.Length != 1) List lsts = new List(); string scpy = new stringsall.Length -1; stmp = sallsall.Length - 1;/保存最后一个的值 Array.Copy(sall, scpy, scpy.Length); /算出最后一个括号的位置 int ist = string.Join(,scpy).Length + 1; int ien = str.IndexOf(), ist); stmp = stmp.PadLeft(ist + stmp.Length, ); /取出括号里的计 算式 string st = str.Substring(ist, ien - ist); /保存本次不需计 算的 lsts.AddRange(scpy); sall = lsts.ToArray(); /计算取出的式子并保存 sallsall.Length-1 += CalculateValue(st); /保存括号）后面的内容 sallsall.Length - 1 += stmp.Substring(ien + 1); return CalculateValue(sall0); public string CalculateValue(string str) /按四则运算符分隔成数组 string sval = SplitCalculate(str); /进行乘法，除法运 算 sval = Calculate(sval); /进行加，减 ?算 sval = CalculateAddSub(sval); return sval0; private string SplitCalculate(string str) List lst = new List(); string st = str.Split(new char +, -, *, / ); int start = 0; for(int jdx = 0;jdx st.Length ;jdx +) lst.Add(stjdx); start += stjdx.Length; if (start str.Length) lst.Add(str.Substring(start, 1); start +; return lst.ToArray(); private string Calculate(string st) List lst = new List(); if(!IsNumber(st0) throw new Exception(); int val1; int val2; int val3 = 0; ; int idx = 0; /1+2/3*5 for(idx = 0;idx st.Length-1 ; idx+) if (stidx + 1.CompareTo(*) = 0 ) if (val3 != 0) val1 = val3; else val1 = ToInteger(stidx); val2 = ToInteger(stidx + 2); val3 = val1 * val2; idx +; /lst.Add(val3.ToString(); else if (stidx + 1.CompareTo(/) = 0) if (val3 != 0) val1 = val3; else val1 = ToInteger(stidx); val2 = ToInteger(stidx + 2); val3 = val1 / val2; idx +; /lst.Add(val3.ToString(); else if (val3 != 0) lst.Add(val3.ToString(); val3 = 0; else lst.Add(stidx); lst.Add(stidx+1); idx+; if (val3 != 0) lst.Add(val3.ToString(); if (idx = st.Length - 1) lst.Add(stst.Length-1); return lst.ToArray(); private string CalculateAddSub(string st) List lst = new List(); if (!IsNumber(st0) throw new Exception(); int val1; int val2; int val3 = 0; ; /1+2/3*5 for (int idx = 0; idx st.Length - 1; idx+) if (stidx + 1.CompareTo(+) = 0) if (val3 != 0) val1 = val3; else val1 = ToInteger(stidx); val2 = ToInteger(stidx + 2); val3 = val1 + val2; idx +; /lst.Add(val3.ToString(); else if (stidx + 1.CompareTo(-) = 0) if (val3 != 0) val1 = val3; else val1 = ToInteger(stidx); val2 = ToInteger(stidx + 2); val3 = val1 - val2; idx +; /lst.Add(val3.ToString(); else if (val3 != 0) lst.Add(val3.ToString(); val3 = 0; else lst.Add(stidx); lst.Add(stidx + 1); idx+; if (val3 != 0) lst.Add(val3.ToString(); return lst.ToArray(); private int ToInteger(string val) try return Convert.ToInt32(val)