main(){long int num;int indiv,ten,hundred,thousand,ten_thousand,place;printf("num=");scanf("%ld",&num);if(num>9999) place=5;else if(num>999) place=4;else if(num>99) place=3;else if(num>9) place=2;else place=1;printf("place=%d\n",place);printf("Every bit is:");ten_thousand=num/10000;thousand=(int)(num-ten_thousand*10000)/1000;hundred=(int)(num-ten_thousand*10000-thousand*1000)/100;ten=(int)(num-ten_thousand*10000-thousand*1000-hundred*100)/10;indiv=(int)(num-ten_thousand*10000-thousand*1000-hundred*100-ten*10);switch(place){case 5:printf("%d,%d,%d,%d,%d\n",ten_thousand,thousand,hundred,ten,indiv); printf("reserve bit is:"); printf("%d,%d,%d,%d,%d\n",indiv,ten,hundred,thousand,ten_thousand); break; case 4:printf("%d,%d,%d,%d\n",thousand,hundred,ten,indiv); printf("reserve bit is:"); printf("%d,%d,%d,%d\n",indiv,ten,hundred,thousand); break; case 3:printf("%d,%d,%d\n",hundred,ten,indiv); printf("reserve bit is:"); printf("%d,%d,%d\n",indiv,ten,hundred); break; case 2:printf("%d,%d\n",ten,indiv); printf("reserve bit is:"); printf("%d,%d\n",indiv,ten); break; case 1:printf("%d\n",indiv); printf("reserve bit is:"); printf("%d\n",indiv); break; }}請問為什么在求個(gè)位數(shù),十位數(shù),百位數(shù),千位數(shù)是要加上(int)?