将一个字符串循环右移的三种方法

#include <iostream> #include <string> using namespace std; void LoopMoveRight(char *vStr, int steps); void LoopMoveRightByStrCopy(char *vStr, int steps); void LoopMoveRightByMemcpy(char *vStr, int steps); int main() { char g_str[20] = "\0"; int steps; cout<<"Please input the string: "; cin>>g_str; cout<<"Please input the steps moving rightly: "; cin>>steps; LoopMoveRight(g_str,steps); cout<<"After moving, the string is : "<<g_str<<endl; cout<<"Please input the steps moving rightly: "; cin>>steps; LoopMoveRightByStrCopy(g_str, steps); cout<<"After moving, the string is : "<<g_str<<endl; cout<<"Please input the steps moving rightly: "; cin>>steps; LoopMoveRightByMemcpy(g_str, steps); cout<<"After moving, the string is : "<<g_str<<endl; return 0; } void LoopMoveRight(char *vStr, int steps) { int len = strlen(vStr); char tempChar; while(steps > 0) { int i = len - 1; tempChar = vStr[i]; for (; i > 0; i--) { vStr[i] = vStr[i - 1]; } vStr[0] = tempChar; steps--; } } void LoopMoveRightByStrCopy(char *vStr, int steps) { int RemanLen = strlen(vStr) - steps; char tmpStr[10]; strcpy(tmpStr, vStr + RemanLen);//get the sub string which will be put in the front strcpy(tmpStr + steps, vStr); *(tmpStr + strlen(vStr)) = '\0';//same as tmpStr[strlen(vStr)] strcpy(vStr, tmpStr); } void LoopMoveRightByMemcpy(char *vStr, int steps) { int RemanLen = strlen(vStr) - steps; char tmpStr[10]; memcpy(tmpStr, vStr + RemanLen, steps); memcpy(vStr + steps, vStr, RemanLen); memcpy(vStr, tmpStr, steps); }