如"i am a student" 倒置为 "student a am i"

思路：

1）倒置整个字符串

2）倒置每个单词

#include <iostream>
#include <string.h>
using namespace std;


void Reverse_word(char *p,char *q){
    
    if (p==q) {
        return;
    }
    
    while (p<q) {
        char tmp=*p;
        *p=*q;
        *q=tmp;
        
        q--;
        p++;
    }
    
}

void Reverse_sentance(char pSentance[]){
    
    if (pSentance==NULL) {
        return;
    }
    
    Reverse_word(pSentance,pSentance+strlen(pSentance)-1);
    
    char *pBegin=pSentance;
    char *pEnd=pSentance;
    
    while (*pEnd!='\0') {
        if (*pEnd!=' ') {
            pEnd++;
        }else{
            Reverse_word(pBegin,pEnd-1);
            pBegin=++pEnd;
        }
    }
    
    Reverse_word(pBegin,pEnd-1);//逆转最后一个词
}


int main(){
    
    char p[]="i am a student";
    printf("%s\n",p);
    Reverse_sentance(p);
    printf("%s\n",p);
    
    return 0;
}