二分边界防止循环

数的范围为例#includeiostream #includealgorithm #includevector using namespace std; int main(){ int n,q; scanf(%d%d,n,q); vectorint a(n); for(int i0;in;i) scanf(%d,a[i]); while(q--){ int k; scanf(%d,k); int l0,rn-1; while(lr){ int midlr1; if(a[mid]k){ rmid; } else{ lmid1; } } if(a[l]k) printf(%d ,l); else{ printf(-1 -1\n);//未找到 continue; } int l20,r2n-1; while(l2r2){ int mid l2 r2 1 1; if(a[mid]k){ l2mid; } else{ r2mid-1; } } printf(%d \n,l2); } }