API tools faq
paste
Guest User

Untitled

a guest
Jan 19th, 2018
104
0
Never
Add comment
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
text 8.13 KB | None | 0 0
raw download clone embed print report
  1. package com.example.a24107.computeapplication2;
  2. import java.text.ParseException;
  3. /**
  4. * Created by 24107 on 2017/12/8.
  5. */
  6.  
  7. public class StrToNum {
  8. /**
  9. * 从左往右遍历，先把括号找出来，再计算括号中的值，去掉括号，再计算*和/，再计算+和-，
  10. */
  11.  
  12. //public static int kuoCount = 0;
  13. public static int[] kuoweizhi;
  14. public static String str = "5×((2+2)+2)+((2+2)÷2)";
  15. //5×((2+2)+2)+2+2÷2
  16.  
  17. public static void main(String[] args){
  18. String answer = LeftToRightCompute(str);
  19. System.out.println(answer);
  20. }
  21.  
  22. public static void Swap(int a,int b){
  23. int temp=a;
  24. a=b;
  25. b=temp;
  26. }
  27.  
  28. public static String LeftToRightCompute(String str) {
  29. int numcount = -1;
  30. float firstnum = 1;
  31. float answer = 0;
  32. for (int i = 0; i < str.length(); i++) {
  33. if (str.charAt(i) >= '0' && str.charAt(i) <= '9'||str.charAt(i)=='.') {
  34. if (numcount==-1) {
  35. numcount = i;
  36. }
  37. firstnum = Float.parseFloat(str.substring(numcount, i+1));
  38. answer = firstnum;
  39. //return answer;
  40. }
  41. else {
  42. switch (str.charAt(i)) {
  43. case '+'://当我加的时候，其实是加后面的整个结果
  44. numcount = -1;
  45. answer=firstnum + Float.parseFloat(LeftToRightCompute(str.substring(i + 1)));
  46. return answer+"";
  47. //break;
  48. case '-'://当我减的时候，其实是减后面的整个结果
  49. numcount = -1;
  50. answer=firstnum - Float.parseFloat(LeftToRightCompute(str.substring(i + 1)));
  51. return answer+"";
  52. //break;
  53. case '×'://当我乘的时候，其实是乘第一个数
  54. numcount = -1;
  55. float secondnummulti = Float.parseFloat(FirstnumLeftToRight(str.substring(i+1)));
  56. float answer1 = firstnum * secondnummulti;
  57. String newstringmuti="";
  58. if(str.charAt(i+1)=='('){
  59. int kuocount=1;
  60. i=i+2;
  61. //int temp=i;
  62. for (;i<str.length();i++){
  63. if(str.charAt(i)=='('){
  64. kuocount++;
  65. }
  66. else if(str.charAt(i)==')'){
  67. kuocount--;
  68. }
  69. if(kuocount==0){
  70. newstringmuti = str.substring(i+1);
  71. break;
  72. }
  73. }
  74. }
  75. else if (secondnummulti==(int)secondnummulti) {
  76. newstringmuti = str.substring(i + 1 + Float.toString(secondnummulti).length()-2);
  77. }
  78. else{
  79. newstringmuti = str.substring(i + 1 + Float.toString(secondnummulti).length());
  80. }
  81. newstringmuti = answer1+ newstringmuti;
  82. answer = Float.parseFloat(LeftToRightCompute(newstringmuti));
  83. return answer+"";
  84. //break;
  85. case '÷'://当我除的时候，其实是除第一个数
  86. numcount = -1;
  87. float secondnumchu = Float.parseFloat(FirstnumLeftToRight(str.substring(i+1)));
  88. float answer2 = firstnum / secondnumchu;
  89. String newstringchu="";
  90. if(str.charAt(i+1)=='('){
  91. int kuocount=1;
  92. i=i+2;
  93. //int temp=i;
  94. for (;i<str.length();i++){
  95. if(str.charAt(i)=='('){
  96. kuocount++;
  97. }
  98. else if(str.charAt(i)==')'){
  99. kuocount--;
  100. }
  101. if(kuocount==0){
  102. newstringchu = str.substring(i);
  103. break;
  104. }
  105. }
  106. }
  107. else if (secondnumchu==(int)secondnumchu) {
  108. newstringchu = str.substring(i + 1 + Float.toString(secondnumchu).length()-2);
  109. }
  110. else{
  111. newstringchu = str.substring(i + 1 + Float.toString(secondnumchu).length());
  112. }
  113. newstringchu = answer2+ newstringchu;
  114. answer = Float.parseFloat(LeftToRightCompute(newstringchu));
  115. return answer+"";
  116. case '(':
  117. int temp=i;
  118. int kuocount=1;//检测这个字符串是否到头或者有区域外的括号如(a+b)+(c+d)
  119. i=i+1;
  120. for (;i<str.length();i++){
  121. if(str.charAt(i)=='('){
  122. kuocount++;
  123. }
  124. else if(str.charAt(i)==')'){
  125. kuocount--;
  126. }
  127. if(kuocount==0){
  128. float answer3= Float.parseFloat(LeftToRightCompute(str.substring(temp+1,i)));//但str本身并未被改变
  129. return LeftToRightCompute(answer3+str.substring(i));
  130. }
  131. }
  132. //break;
  133. case ')':
  134. //continue;
  135. }
  136. }
  137. }
  138. return answer+"";
  139. }
  140.  
  141. public static String FirstnumLeftToRight(String str) {
  142. System.out.println(str);
  143. int numcount = -1;
  144. float firstnum = 0;
  145. if (str.charAt(0)=='('){
  146. int i=0;
  147. float answer=0;
  148. int temp=i;
  149. int kuocount=1;//检测这个字符串是否到头或者有区域外的括号如(a+b)+(c+d)
  150. i=i+1;
  151. for (;i<str.length();i++){
  152. if(str.charAt(i)=='('){
  153. kuocount++;
  154. }
  155. else if(str.charAt(i)==')'){
  156. kuocount--;
  157. }
  158. if(kuocount==0){
  159. float answer3= Float.parseFloat(LeftToRightCompute(str.substring(temp+1,i)));//但str本身并未被改变
  160. return answer3+"";
  161. }
  162. }
  163. /*
  164. int i=0;
  165. int temp=i;
  166. int kuocount=1;//检测这个字符串是否到头或者有区域外的括号如(a+b)+(c+d)
  167. i=i+1;
  168. for (;i<str.length();i++){
  169. if(str.charAt(i)=='('){
  170. kuocount++;
  171. }
  172. else if(str.charAt(i)==')'){
  173. kuocount--;
  174. }
  175. if(kuocount==0){
  176. StringBuffer sb=new StringBuffer();
  177. sb.append(str).replace(temp,i+1,"");
  178. str=sb.toString();
  179. System.out.println(sb.toString());
  180. System.out.println(str);
  181. }
  182. }
  183. */
  184. return answer+"";
  185. }
  186. else {
  187. for (int i = 0; i < str.length(); i++) {
  188. if (str.charAt(i) >= '0' && str.charAt(i) <= '9'||str.charAt(i)=='.') {
  189. if (numcount==-1) {
  190. numcount = i;
  191. }
  192. firstnum = Float.parseFloat(str.substring(numcount, i + 1));
  193. }
  194. else {
  195. return firstnum+"";
  196. }
  197. }
  198. }
  199. return firstnum+"";
  200. }
  201. }
Add Comment
Please, Sign In to add comment
Public Pastes
We use cookies for various purposes including analytics. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy.  OK, I Understand
Not a member of Pastebin yet?
Sign Up, it unlocks many cool features!