输入正整数a,b,c,输出a/b的小数形式,精确到小数后c位。(提示:使用循环)
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| #include<bits/stdc++.h> using namespace std; #define MAX_LEN 100 char ans[MAX_LEN+10]; int main() { memset(ans,0,sizeof(ans)); int a,b,c; int anslen;
cin>>a>>b>>c;
sprintf(ans,"%d.",a/b); ans[MAX_LEN+8]=anslen=strlen(ans); a%=b; for (int i=0; i<c; i++) {
sprintf(ans+anslen+i,"%d",a*10/b); a=a*10%b; } ans[MAX_LEN+9]= anslen=strlen(ans); int flags=0; for (int i=ans[MAX_LEN+9]-1; i>ans[MAX_LEN+8]-1; i--) { if(flags) { if(ans[i]=='9') { ans[i]='0'; flags=1; } else { ans[i]++; flags=0; break; }
} if(ans[i]=='9') { ans[i]='0'; flags=1;
} else if(ans[i]>='5') { ans[i]++; flags=0; break; }
} for (int i=ans[MAX_LEN+8]-2; i>=0; i--) { if(flags) { if(ans[i]=='9') { ans[i]='0'; flags=1; } else { ans[i]++; flags=0; break; }
} if(ans[i]=='9') { ans[i]='0'; flags=1;
} else if(ans[i]>='5') { ans[i]++; flags=0; break; }
} printf("%s",ans);
return 0; }
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