求输入100个数中正数的个数及其平均值 main( ) {int i,n; float sum,f; n=0; __1__; for(i=0;i <= 100,i++) {printf("enter a real number:"; scanf("%f",&f)); if__2__ continue; __3__; n++; } print f("sum=%f",sum); print f("a rerage=%f",sum/n); }