字符串
1、把一串字符串里的数字找出来加起来
long long int AddNumInChar(const char* str) { assert(str!=NULL); int length=strlen(str); long long int result=0; for(int i=0;i<length;i++) { if(str[i]>='0'&&str[i]<='9') { result+=str[i]-'0'; } } return result; }
2、把字符串转换成整数
void Char2Int(const char*str) { assert(str!=NULL); int length=strlen(str); long long int result=0; bool flag=false; bool fuhao=true; for(int i=0;i<length;i++) { if(i==0&&(str[0]=='+'||str[0]=='-')) { fuhao=str[0]=='-'?false:true; } else if(str[i]>='0'&&str[i]<='9') { flag=true; result=result*10+str[i]-'0'; } else { printf("My God "); return; } } if(!fuhao) result=result*(-1); printf("%lld ",result); }
3、把字符串顺序倒过来
char* reverseString(char* str) { assert(str!=NULL); int length=strlen(str); for(int i=0;i<length/2;i++) { char temp=str[i]; str[i]=str[length-i-1]; str[length-i-1]=temp; } return str; }
4、找字符串里的回数
char *FindString(const char *str) { assert(str!=NULL); int length=strlen(str); int *numbers=new int[length]; float *index=new float[length]; numbers[0]=numbers[length-1]=1; index[0]=0; index[length-1]=length-1; int left,right; for(int i=1;i<length-1;i++) { left=i-1; right=i+1; if(str[left]!=str[right]&&str[left]!=str[i]&&str[i]!=str[right]) { numbers[i]=1; index[i]=i; } else { if(str[left]==str[right]) { numbers[i]=3; index[i]=i; } else if(str[left]==str[i]) { numbers[i]=2; index[i]=(left+i)/2.0; right=i; } else if(str[i]==str[right]) { numbers[i]=2; index[i]=(right+i)/2.0; left=i; } while(--left>=0&&++right<length) { if(str[left]==str[right]) numbers[i]+=2; else break; } } } int max=numbers[0]; int tempI=0; for(int i=0;i<length;i++) { if(numbers[i]>max) { tempI=i; max=numbers[i]; } } char *result=new char[max]; for(int i=0;i<max;i++) { int temp=floor(i+index[tempI]-max/2+0.5); result[i]=str[temp]; } delete []numbers; return result; }
5、替换空格为%20:
char* ChangeString(char* myChar,int length) { char* result=new char[length*3]; int count=0; for(int i=0;i<length;i++) { if(myChar[i]==' ') { result[count++]='%'; result[count++]='2'; result[count++]='0'; } else { result[count++]=myChar[i]; } } result[count]=' '; return result; }
6、翻转单词顺序
void Reverse(char* const numbers,int length) { char temp; for(int i=0;i<length/2;i++) { temp=numbers[i]; numbers[i]=numbers[length-i-1]; numbers[length-i-1]=temp; } } void PrintReverse(char* const numbers,int length) { int i=0; Reverse( numbers,length); int letterLen=0,begin=0;i=0; bool flag=true; while(numbers[i]!=' ') { if(numbers[i]!=' ') { flag=true; letterLen++; } else if(flag) { if(letterLen>1) Reverse(numbers+begin,letterLen); letterLen=0; begin=i+1; flag=false; } else begin++; i++; } Reverse(numbers+begin,letterLen); printf("%s ",numbers); }
左旋转字符串
void Reverse(char* const numbers,int length)
{
char temp;
for(int i=0;i<length/2;i++)
{
temp=numbers[i];
numbers[i]=numbers[length-i-1];
numbers[length-i-1]=temp;
}
}
void PrintMov(char* const numbers,int move)
{
int length=strlen(numbers);
move=move%length;
Reverse( numbers,length);
Reverse(numbers,length-move);
Reverse(numbers+length-move,move);
printf("%s
",numbers);
}
7、第一次只出现一次的字符
int FirstOneCharacter(const char* characters) { int appearances[LetterNum]={0}; int result=-1; if(characters==NULL) return result; int length=strlen(characters); for(int i=0;i<length;i++) { appearances[characters[i]-'A']++; } for(int i=0;i<length;i++) { if(appearances[characters[i]-'A']==1) { result=i; break; } } return result; }
8、字符串的全排列:
void Permutation(char* source,char *begin); void Permutation(char* source) { int length=strlen(source); if(source==NULL||length<=0) return; Permutation(source,source); } int *Sort(char *arrays) { int length=strlen(arrays); char temp; int *index=new int[length]; int tempIndex; for(int i=0;i<length;i++) { index[i]=i; } for(int i=0;i<length;i++) { for(int j=i;j<length;j++) { if(arrays[j]<arrays[i]) { temp=arrays[j]; arrays[j]=arrays[i]; arrays[i]=temp; tempIndex=index[j]; index[j]=index[i]; index[i]=tempIndex; } } } return index; } void Permutation(char* source,char *begin) { if(begin[0]==' ') printf("%s ",source); else { int length=strlen(begin); char *temp=new char[length+1]; int i=0; char word; int *index; temp=strcpy(temp,begin); index=Sort(temp); for(;i<length;i++) { if(i>0&&temp[i]==temp[i-1]) continue; swap(begin[0],begin[index[i]]); Permutation(source,begin+1); swap(begin[0],begin[index[i]]); } delete []temp; delete []index; } }