数据结构-字符串

char str[10];
strcpy(str,"0123456789");

int judge(){
  char str1[]="hello world";
  char str2[]="hello world";
  
  char* str3="hello world";
  char* str4="hello world";
  
  if(str1==str2){
    printf("str1 and str2 are same\n");
  }
  else{
    printf("str1 and str2 are not same\n");
  }
  
  if(str3==str4){
    printf("str3 and str4 are same\n");
  }
  else{
    printf("str3 and str4 are not same\n");
  }
  return 0;
}

public class spaceReplace {
    public static void spaceReplace(String strOld,int len){
        char[] chs =new char[len];
        char[] ch = strOld.toCharArray();
        for (int i = 0; i < ch.length; i++) {
            chs[i] = ch[i];
        }

        int strOldLen = 0;
        int blackString = 0;
        if(chs==null || len<=0)
        {
            new NullPointerException();
        }

        int i=0;
        while(chs[i]!=‘\0‘){
            strOldLen++;
            if(chs[i]==‘ ‘){
                blackString++;
            }
            i++;
        }
        //将空格转换成%20字符的长度
        int strNewLen = strOldLen + blackString*2;
        if(strNewLen>len){
            new ArrayIndexOutOfBoundsException();
        }

        int indexOfOld=strOldLen;//指向‘\0‘
        int indexOfNew=strNewLen;

        while(indexOfOld>0 && indexOfNew>indexOfOld){
            if(chs[indexOfOld] == ‘ ‘){
                chs[indexOfNew--] = ‘0‘;
                chs[indexOfNew--] = ‘2‘;
                chs[indexOfNew--] = ‘%‘;
            }
            else{
                chs[indexOfNew--] = chs[indexOfOld];
            }
            --indexOfOld;
        }
        for (char c : chs) {
            if(c==‘\0‘){
                break;
            }
            System.out.print(c);
        }
        System.out.println();
    }

    public static void main(String[] args) {
        String str = "We are happy.";
        spaceReplace(str,100);//We%20are%20happy.
    }
}

public class arrayMerge {
    public static void main(String[] args){
        int[] A1,A2;
        A1=new int[]{1,3,5,7,9};
//        A1=new int[]{};
        A2=new int[]{2,2,3};
//        A2=new int[]{2,4,6,8,10};
        arrayMerge(A1,A2,100);
    }

    public static void arrayMerge(int[] A1,int[] A2,int num){
        int[] res=new int[100];
        int len1=A1.length;
        int len2=A2.length;
        if(len1==0&&len2!=0){
            System.out.println(A2);
        }
        else if(len1!=0&&len2==0){
            System.out.println(A1);
        }
        else if(len1==0&&len2==0){
            new NullPointerException();
        }
        int mark1=len1-1,mark2=len2-1;
        int mark=len1+len2-1;
        while(mark1>=0&&mark2>=0){
            if(A1[mark1]>A2[mark2]){
                res[mark--]=A1[mark1--];
            }
            else if(A1[mark1]<=A2[mark2]){
                res[mark--]=A2[mark2--];
            }
        }
//        System.out.print("a");
        while(mark1<0&&mark2>=0){
            res[mark--]=A2[mark2--];
        }
//        System.out.print("b");
        while(mark1>=0&&mark2<0){
            res[mark--]=A1[mark1--];
        }
//        System.out.print("c");
        for(int i=0;i<len1+len2;i++){
            System.out.print(res[i]+" ");
        }
    }
}