#include "iostream"
#include "string.h"
using namespace std;
int main()
{
char instr[100]={0};
char c;
int i;
cout<<"请输入一个字符串:"<<endl;
cin>>instr;
cout<<"请输入你想修改成大写字母的字符:"<<endl;
cin>>c;
for(i=0;i<strlen(instr);i++)
if(instr[i]==c)
instr[i]-=32;
cout<<"转换后的字符串为:"<<instr<<endl;
return 0;
}
运行结果: