1.9
#includeint main () { int sum=0,val=50; while(val<=100){ sum+=val; ++val; } std::cout<
1.10#includeint main() { int reduce=0 ,val=10; while(val>=0){ //reduce-=val; 减等于是reduce减val, std::cout<<" "<

1.9
#includeint main () { int sum=0,val=50; while(val<=100){ sum+=val; ++val; } std::cout<
1.10#includeint main() { int reduce=0 ,val=10; while(val>=0){ //reduce-=val; 减等于是reduce减val, std::cout<<" "<