int s=0, i=1; while (i<=100) { s= s+i; i=i +1; }; сout<<s;

int s=0, i=1; do { s= s+i; i=i +1; } while (i<=100); сout<<s;

int s=0, i=1; while (i<100) { s= s+i; i=i +1; }; сout<<s;

int s=0; for (int i=1; i<=100; i++) s=s+i; сout<<s;

int s=0; for (int i=1; i<100; i++) s=s+i; сout<<s;